What does an "if-else" statement do in coding?

An "if-else" statement is a fundamental control structure in coding that allows for conditional execution of code. It checks a specific condition, and if that condition evaluates to true, it executes a block of code associated with the "if" part. Conversely, if the condition is false, it executes the block of code tied to the "else" part. This mechanism is crucial for guiding the flow of a program based on varying inputs or states, enabling the programmer to set different pathways for execution.

For instance, in a simple scenario like determining if a user is eligible for a discount based on their age, an "if-else" statement would assess whether the user's age meets the required criteria. If true, the discount logic would run; if false, the alternative logic would execute. This creates a clear and organized way to manage decision-making processes within the code.

The other options reference different programming concepts. Defining a function involves creating a reusable block of code, calling another program refers to executing an external application or script, and assigning a variable deals with storing data in memory. Each of these serves distinct purposes within programming, but they do not provide the conditional branching capability that an "if-else" statement offers.