This chapter focuses on computer science lab-based learning in similar to lab-based learning commonly used in natural sciences teaching. Lab-based learning emphasizes the use of computers as a laboratory, serving as a learning environment that facilitates investigation and exploration. One of the main messages delivered in this chapter is that computer-based learning enables learners to explore their problem-solving strategies, express their solutions to a given problem, get feedback regarding the correctness of their solution and to reflect on it, to develop large projects, to explore new topics, and to deepen their understanding of the nature of the algorithms they develop. The main purpose of the lessons in the MTCS course dedicated to this topic is to expose the students to usages of the computer lab as a learning environment and to let them realize how it may improve their future pupils’ understanding of computer science ideas. One of the main messages of this chapter is that the learning of computer science in the computer lab is not limited to programming tasks; rather, the computer lab can be used for additional pedagogical ways that further enhance learners’ understanding of computer science. In this chapter, we refer to computer science lab-based learning as the "computer lab" and we present teaching methods that are especially suitable to be employed in the computer lab, where all learners work on computers, either on the school’s computer in a specific room allocated for this purpose or on their own laptops. Specifically, the following topics are addressed in this chapter: what is a computer lab?, the lab-first teaching approach, visualization and animation, and using AI-based environments that support learning processes.