A 32-bit signed integer is a data type used in computer programming to represent whole numbers. It can store values ranging from -2,147,483,648 to 2,147,483,647. The "32-bit" part indicates that the integer is stored using 32 bits of memory, while "signed" means it can hold both positive and negative values. In binary, a 32-bit signed integer uses one bit for the sign (positive or negative) and the remaining 31 bits for the actual number. This allows for efficient storage and manipulation of integers in various applications, such as software development and data processing.