One of the most popular graphic formats for storing and transmitting images in a compressed form.

Originally developed for the transfer of raster images over computer networks back in 1987.

In 1989, the gif format received an update that added support for image transparency and animation.

Today it is actively used when filling pages websites graphic content.

Given that search engines can not index image contents, parameter filling alt tag img gives them the ability to understand what is stored in the gif format file (as well as jpeg and png).