An executable file is a type of computer file that contains a program capable of being run or executed by a computer. These files typically have specific extensions, such as .exe for Windows, .app for macOS, or .out for Linux. When opened, the operating system reads the instructions within the file and performs the tasks specified by the program. Executable files are essential for running software applications, games, and scripts. They can be created using programming languages like .C or .Python and are often compiled into a format that the computer can understand. However, caution is advised, as some executable files may contain malware or harmful code.