Introduction:
A computer program is a set of instructions written in a computer language that can be executed by a computer to perform a useful task. It is an essential component of computer programming and plays a crucial role in enabling computers to carry out specific operations or solve problems.

Explanation:
A computer program is a collection of instructions that are written in a specific computer language such as C++, Python, Java, or JavaScript. These instructions are written in a human-readable format and are then translated into machine code that the computer can understand and execute.

Functionality and Usefulness:
Computer programs are designed to perform a variety of tasks, ranging from simple calculations to complex data processing. They can be used to automate repetitive tasks, manipulate data, control hardware devices, build user interfaces, and much more.

Execution and Interpretation:
Computer programs are executed by the computer's central processing unit (CPU). The CPU reads the instructions from the program and performs the corresponding operations. The program's instructions are executed sequentially, one after another, until the task is completed.

Types of Computer Programs:
There are different types of computer programs, including:

1. Operating System Programs: These programs manage the computer's hardware and software resources, allowing users to interact with the computer and run other applications.

2. Application Programs: These programs are designed to perform specific tasks or solve particular problems. Examples include word processors, spreadsheets, graphic design software, and video games.

3. Utility Programs: These programs provide additional functionality to the computer system, such as antivirus software, disk cleanup tools, and file compression utilities.

Conclusion:
In summary, a computer program is a set of instructions written in a computer language that enables a computer to perform a specific task. It is an essential component of computer programming and is used to automate tasks, manipulate data, and control hardware devices. Computer programs are executed by the computer's CPU and can be categorized into operating system programs, application programs, and utility programs.