Control structures are fundamental components in programming that dictate the flow of execution within a program. They enable developers to control how and when specific blocks of code are executed based on certain conditions or iterations. The primary types of control structures include sequence, selection, and repetition. Sequence structures execute statements in a linear order, while selection structures, such as if-else statements, allow for decision-making based on conditions. Repetition structures, like loops, enable the execution of code multiple times until a specified condition is met. Understanding these structures is essential for writing efficient and effective code in any programming language.