Explain what the abbreviation PEP means in the context of Python language and its development.

PEP is an abbreviation for Python Enhancement Proposal, which translates as "Proposal for improving Python".

A PEP is a document that describes a new feature, improvement, or change in the Python language or its ecosystem. PEPs serve to discuss and standardize changes before they are implemented.

Each PEP has a unique number and goes through stages of discussion, acceptance, or rejection. For example, PEP 8 describes the coding style in Python.

Thus, a PEP is a key mechanism for the development and standardization of the language.