In C programming, a structure (often referred to as a struct) is a composite data type that groups together variables of different types into a single unit. This is particularly useful for representing real-world entities that have multiple attributes. For example, a structure can represent a book with attributes like title, author, and price, each of which may be of different data types (string, string, float).

To define a structure, the `struct` keyword is used, followed by the structure name and its members enclosed in curly braces. Here’s a basic syntax:```cstruct StructureName {dataType member1;dataType member2;// more members};```For example, to define a structure for a Person:```cstruct Person {char name[^^50^^];int age;float height;};```This defines a structure named `Person` with three members: `name`, `age`, and `height`.

Once a structure is defined, you can create variables of that structure type. For example:```cstruct Person person1, person2;```This creates two variables, `person1` and `person2`, each capable of holding data for a person.

To access or modify the members of a structure, the dot operator (.) is used. For example:```cperson1.age = 30;strcpy(person1.name, "Alice");```If you have a pointer to a structure, you can use the arrow operator (->) to access its members.

Structures are widely used in C programming for various applications, such as:

• Data Organization: Grouping related data together, making it easier to manage and pass around in functions.
• Complex Data Structures: Building more complex data structures like linked lists, trees, and graphs.
• Real-World Modeling: Representing real-world entities in software applications, such as students, employees, or products in a store.In summary, C structures are a powerful feature that enhances the language's capability to handle complex data types efficiently, making it easier to write organized and maintainable code.