Today's post is about a Machine Learning area, the Reinforcement Learning (RL). This article seeks to summarise the principal types of algorithms used for reinforcement learning. Here we will get an overview of the existing RL methods on an intuitive level. In further posts, we will go into more detail and code examples. Robot - Photo by Photos Hobby on Unsplash As other Artificial Intelligence's approaches, RL is not a new thing. The first studies and developments dating back to the 1850s and further advances on mid-1950s, where Richard Bellman has a huge impact [1]. Now, we are achieving several advances in the area and improving the results year after year. Reinforcement learning is nowadays the most virtuous way to suggest or find the machine’s creativity. Please note, different from human beings, theses algorithms can fetch experience from millions of parallel simulations if they are running on a powerful infrastructure. Terminologies Figure 1 - Agent-environment inter