This lecture covers the concept of data types in C/Arduino, focusing on understanding microcontrollers. It explains different data types such as boolean, byte, char, and word, along with their usage in programming. The lecture also delves into arrays, variables, and memory allocation, providing practical examples and quizzes to reinforce learning. Additionally, it discusses the significance of data types in microcontroller programming, emphasizing the importance of choosing the right type for efficient memory usage and arithmetic operations.