Ending is a kind of affix which is added to a word in declension or conjugation. Unlike suffixes, endings are used to make various forms of the same word, they do not form new words.

Examples:

boys (plural)

he makes (third person singular)

he closed (past tense)

A large amount of endings are found in inflective languages, such as Czech, Finnish, Latin, Hungarian, Russian, etc.

Linguistic morphology | Affixes

Koncovka (mluvnice) | Pääte (morfologia)