English Dictionary

file extension

noun

A short series of text characters at the end of a computer filename, used to indicate the type of contents and the software that will be required to operate or open it.

The file extension of this document is .pdf.

意味（1）

A short series of text characters at the end of a computer filename, used to indicate the type of contents and the software that will be required to operate or open it.

A text file may have a file extension of .txt.