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 repetitions. The three primary types of control structures are sequence, selection, and repetition. Sequence structures execute statements in a linear order, selection structures allow for decision-making through conditional statements, and repetition structures enable the execution of code multiple times through loops. Understanding control structures is essential for effective algorithm design and structured programming, as they enhance the ability to solve complex problems efficiently.