Definition - What does Annotation mean?
Annotation is a term used in computer programming to refer to documentation and comments that may be found on code logic. Annotation is typically ignored once the code is executed or compiled.
Sometimes programmers will anticipate that those learning a programming language such as HTML, or those who may be modifying the programming at a later date, will require an explanation of the rationale behind the logic or even an explanation of how the logic accomplishes its purpose or goal. Thus, an annotation, or explanation, will be included within the code.
Techopedia explains Annotation
In source control, derivatives of annotation, such as annotate or annotated may be used. Annotate (also called "blame") is a function used to determine who committed code changes. That person may be annotated, which means that he or she is blamed for committing the code or programming changes which caused the program to fail or behave in an unintended way.
In Java, an annotation is a special kind of modifier, which by convention precedes other modifiers. The annotations consist of an "@" sign, followed by a particular type (of which there are many) and a parenthesized list of element-value pairs. These are followed by a right parenthesis.