In computer programming, an algorithm is a set of well-defined instructions to solve a particular problem. It is a finite set of instructions carried out in a specific order to perform a particular task. An algorithm is not the entire program or code, but rather simple logic to a problem represented as an informal description in the form of a flowchart or pseudocode. Algorithms are used to solve specific problems and perform tasks efficiently in the realm of computer science and mathematics.

Here are some key characteristics of an algorithm:

• Precision: The steps are precisely stated.
• Uniqueness: Results of each step are uniquely defined and only depend on the input and the result of the preceding steps.
• Finiteness: The algorithm stops after a finite number of instructions are executed.
• Input: The algorithm receives input.
• Output: The algorithm produces output.
• Generality: The algorithm applies to a set of inputs.

Algorithms can be expressed in various forms, such as natural languages, programming languages, pseudocode, flowcharts, and control tables. They are language-independent, meaning they can be implemented in any language, and yet the output will be the same, as expected.

Examples of algorithms include finding the largest among three numbers, finding all the roots of a quadratic equation, checking prime numbers, and adding two numbers entered by the user. Algorithm writing is a process that occurs after the problem domain has been well-defined.