

Reinforcement learning is a very useful (and currently popular) subtype of machine learning and artificial intelligence. It is based on the principle that agents, when placed in an interactive environment, can learn from their actions via rewards associated with the actions, and improve the time to achieve their goal.
In this article, we’ll explore the fundamental concepts of reinforcement learning and discuss its key components, types, and applications.
Definition of Reinforcement Learning
We can define reinforcement learning as a machine learning technique involving an agent who needs to decide which actions it needs to do to perform a task that has been assigned to it most effectively. For this, rewards are assigned to the different actions that the agent can take at different situations or states of the environment. Initially, the agent has no idea about the best or correct actions. Using reinforcement learning, it explores its action choices via trial and error and figures out the best set of actions for completing its assigned task.
The basic idea behind a reinforcement learning agent is to learn from experience. Just like humans learn lessons from their past successes and mistakes, reinforcement learning agents do the same – when they do something “good” they get a reward, but, if they do something “bad”, they get penalized. The reward reinforces the good actions while the penalty avoids the bad ones.
Reinforcement learning requires several key components:
- Agent – This is the “who” or the subject of the process, which performs different actions to perform a task that has been assigned to it.
- Environment – This is the “where” or a situation in which the agent is placed.
- Actions – This is the “what” or the steps an agent needs to take to reach the goal.
- Rewards – This is the feedback an agent receives after performing an action.
Before we dig deep into the technicalities, let’s warm up with a real-life example. Reinforcement isn’t new, and we’ve used it for different purposes for centuries. One of the most basic examples is dog training.
Let’s say you’re in a park, trying to teach your dog to fetch a ball. In this case, the dog is the agent, and the park is the environment. Once you throw the ball, the dog will run to catch it, and that’s the action part. When he brings the ball back to you and releases it, he’ll get a reward (a treat). Since he got a reward, the dog will understand that his actions were appropriate and will repeat them in the future. If the dog doesn’t bring the ball back, he may get some “punishment” – you may ignore him or say “No!” After a few attempts (or more than a few, depending on how stubborn your dog is), the dog will fetch the ball with ease.
We can say that the reinforcement learning process has three steps:
- Interaction
- Learning
- Decision-making
Types of Reinforcement Learning
There are two types of reinforcement learning: model-based and model-free.
Model-Based Reinforcement Learning
With model-based reinforcement learning (RL), there’s a model that an agent uses to create additional experiences. Think of this model as a mental image that the agent can analyze to assess whether particular strategies could work.
Some of the advantages of this RL type are:
- It doesn’t need a lot of samples.
- It can save time.
- It offers a safe environment for testing and exploration.
The potential drawbacks are:
- Its performance relies on the model. If the model isn’t good, the performance won’t be good either.
- It’s quite complex.
Model-Free Reinforcement Learning
In this case, an agent doesn’t rely on a model. Instead, the basis for its actions lies in direct interactions with the environment. An agent tries different scenarios and tests whether they’re successful. If yes, the agent will keep repeating them. If not, it will try another scenario until it finds the right one.
What are the advantages of model-free reinforcement learning?
- It doesn’t depend on a model’s accuracy.
- It’s not as computationally complex as model-based RL.
- It’s often better for real-life situations.
Some of the drawbacks are:
- It requires more exploration, so it can be more time-consuming.
- It can be dangerous because it relies on real-life interactions.
Model-Based vs. Model-Free Reinforcement Learning: Example
Understanding model-based and model-free RL can be challenging because they often seem too complex and abstract. We’ll try to make the concepts easier to understand through a real-life example.
Let’s say you have two soccer teams that have never played each other before. Therefore, neither of the teams knows what to expect. At the beginning of the match, Team A tries different strategies to see whether they can score a goal. When they find a strategy that works, they’ll keep using it to score more goals. This is model-free reinforcement learning.
On the other hand, Team B came prepared. They spent hours investigating strategies and examining the opponent. The players came up with tactics based on their interpretation of how Team A will play. This is model-based reinforcement learning.
Who will be more successful? There’s no way to tell. Team B may be more successful in the beginning because they have previous knowledge. But Team A can catch up quickly, especially if they use the right tactics from the start.
Reinforcement Learning Algorithms
A reinforcement learning algorithm specifies how an agent learns suitable actions from the rewards. RL algorithms are divided into two categories: value-based and policy gradient-based.
Value-Based Algorithms
Value-based algorithms learn the value at each state of the environment, where the value of a state is given by the expected rewards to complete the task while starting from that state.
Q-Learning
This model-free, off-policy RL algorithm focuses on providing guidelines to the agent on what actions to take and under what circumstances to win the reward. The algorithm uses Q-tables in which it calculates the potential rewards for different state-action pairs in the environment. The table contains Q-values that get updated after each action during the agent’s training. During execution, the agent goes back to this table to see which actions have the best value.
Deep Q-Networks (DQN)
Deep Q-networks, or deep q-learning, operate similarly to q-learning. The main difference is that the algorithm in this case is based on neural networks.
SARSA
The acronym stands for state-action-reward-state-action. SARSA is an on-policy RL algorithm that uses the current action from the current policy to learn the value.
Policy-Based Algorithms
These algorithms directly update the policy to maximize the reward. There are different policy gradient-based algorithms: REINFORCE, proximal policy optimization, trust region policy optimization, actor-critic algorithms, advantage actor-critic, deep deterministic policy gradient (DDPG), and twin-delayed DDPG.
Examples of Reinforcement Learning Applications
The advantages of reinforcement learning have been recognized in many spheres. Here are several concrete applications of RL.
Robotics and Automation
With RL, robotic arms can be trained to perform human-like tasks. Robotic arms can give you a hand in warehouse management, packaging, quality testing, defect inspection, and many other aspects.
Another notable role of RL lies in automation, and self-driving cars are an excellent example. They’re introduced to different situations through which they learn how to behave in specific circumstances and offer better performance.
Gaming and Entertainment
Gaming and entertainment industries certainly benefit from RL in many ways. From AlphaGo (the first program that has beaten a human in the board game Go) to video games AI, RL offers limitless possibilities.
Finance and Trading
RL can optimize and improve trading strategies, help with portfolio management, minimize risks that come with running a business, and maximize profit.
Healthcare and Medicine
RL can help healthcare workers customize the best treatment plan for their patients, focusing on personalization. It can also play a major role in drug discovery and testing, allowing the entire sector to get one step closer to curing patients quickly and efficiently.
Basics for Implementing Reinforcement Learning
The success of reinforcement learning in a specific area depends on many factors.
First, you need to analyze a specific situation and see which RL algorithm suits it. Your job doesn’t end there; now you need to define the environment and the agent and figure out the right reward system. Without them, RL doesn’t exist. Next, allow the agent to put its detective cap on and explore new features, but ensure it uses the existing knowledge adequately (strike the right balance between exploration and exploitation). Since RL changes rapidly, you want to keep your model updated. Examine it every now and then to see what you can tweak to keep your model in top shape.
Explore the World of Possibilities With Reinforcement Learning
Reinforcement learning goes hand-in-hand with the development and modernization of many industries. We’ve been witnesses to the incredible things RL can achieve when used correctly, and the future looks even better. Hop in on the RL train and immerse yourself in this fascinating world.
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The Open Institute of Technology (OPIT) is turning two! It has been both a long journey and a whirlwind trip to reach this milestone. But it is also the perfect time to stop and reflect on what we have achieved over the last two years, as well as assess our hopes for the future. Join us as we map our journey over the last two years and look forward to future plans.
July 2023: Launching OPIT
OPIT officially launched as an EU-accredited online higher education institution in July 2023, and offered two core programs: a BSc in Modern Computer Science and an MSc in Applied Data Science and AI. Its first class matriculated in September of that year.
The launch of OPIT was several years in the making. Founder Riccardo Ocleppo was planning OPIT ever since he launched his first company, Docsity, in 2010, an online platform for students to share access to educational resources. As part of working on that project, Ocleppo had the chance to talk to thousands of students and professors and discovered just how big a gap there is between what is taught in universities today and job market demands. Ocleppo felt that this gap was especially wide in the field of computer science, and OPIT was his concept to fill that gap.
The vision was to provide university-level teaching that was accessible around the world through digital learning technologies and that was also affordable. Ocleppo’s vision also involved international professors and building strong relationships with global companies to ensure a truly international and fit-for-purpose learning experience.
One of the most important parts of launching OPIT was the recruitment of the faculty of professors, which Ocleppo was personally involved in. The idea was to build a roster of expert teachers and professionals who were leaders in the field and urge them to unite the teaching fundamentals with real-world applications and experience. The process involved screening more than 5,000 CVs, interviewing over 200 candidates, and recruiting 25 professors to form the core of OPIT’s faculty.
September 2023: The Inaugural Cohort
When OPIT officially launched, its first cohort included 100 students from 38 different countries. Divided between the BSc and MSc courses, students were also allowed to participate in one of two different tracks. Some chose the standard track to accommodate their existing work commitments, while others chose to fast-track to complete their studies sooner.
OPIT was pleased with its success in making the courses international and accessible, with notable representation from Africa. In the first cohort, 40% of MSc students were also from non-STEM fields, showing OPIT’s success at engaging professionals looking to develop skills for the modern workplace.
July 2024: A Growing Curriculum
Building on this initial success, in 2024, OPIT expanded its academic offering to include a second BSc program in Digital Business, and three new MSc programs in Digital Business & Innovation, Responsible Artificial Intelligence, and Enterprise Cybersecurity. These were all offered in addition to the original two programs.
The new course offerings led to total student numbers growing to over 300, hailing from 78 different countries. This also led to an expansion of the faculty, with professionals recruited from major business leaders such as Symantec, Microsoft, PayPal, McKinsey, MIT, Morgan Stanley, Amazon, and U.S. Naval Research. This focus on professional experience and real-world applications is ideal for OPIT as 80% of the student body are active working professionals.
January 2025: First Graduating Class
OPIT held its first-ever graduation ceremony in Valletta, Malta, on March 8, 2025. The ceremony was a hybrid event, with students attending both in person and virtually. The first graduating class consisted of 40 students who received an MSc in Applied Data Science and AI.
OPIT’s MSc programs include a capstone project that sees students apply their learning to real-world challenges. Projects included the use of large language models for the creation of chatbots in the ed-tech field, the digitalization of customer support processes in the paper and non-woven industry, personal data protection systems, AI applications for environmental sustainability, and predictive models for disaster prevention linked to climate change. Since many OPIT students realized their capstone projects within their organizations, OPIT also saw itself successfully facilitating digital innovation in the field.
July 2025: New Learning Environments
The next step for OPIT is not just to teach others how to leverage AI to work smarter, but to start applying AI solutions in our own business environment. To this end, OPIT unveiled its OPIT AI Copilot at the Microsoft AI Agents and the Future of Higher Education event in Milan in June 2025.
The OPIT AI Copilot is a specialist AI Agent designed to enhance learning in OPIT’s fully digital environment. OPIT AI Copilot acts as a personal tutor and study companion, and but rather than being trained on the World Wide Web, it is specifically trained on OPIT’s educational archive of around 3,500 hours of lectures and 3,000 proprietary documents.
The OPIT AI Copilot then provides real-time, personalized guidance that adapts to where the student is in the course and the progress they have shown in grasping the material. As well as pulling from existing materials, the OPIT AI Copilot can generate content to deepen learning, such as code samples and practical exams. It can also answer questions posed by the students with answers grounded in the official course material. The tool is available 24/7, and also has an intelligent examination mode, which prevents cheating.
In this way, OPIT AI Copilot enriches the OPIT learning environment by providing students with 24/7 personalized support for their learning journey, ideal for busy professionals balancing work and study. It is a step towards facing the challenge of “one-size-fits-all” education approaches that have plagued learning institutions for millennia.
September 2025: A New Cohort
On the heels of the OPIT AI Copilot launch, OPIT is excited about recruiting its next round of students, with applications open until September 2025. If you are interested in joining OPIT, you can learn more about its courses here.

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