A keyword is a word that, in combination with other keywords, can give a high-level description of the contents of a text document, allowing you to identify its subject matter.
The recommended number is 5-7 keywords.
Please use common terms or indexed keywords. Indexed keywords are those words that are most popular and used on this topic. Using the indexed keywords increases the probability of finding an article in databases and libraries.
Example:
Prince is a generally accepted term for the head of the feudal state in medieval Russia.
Komsomol - is a generally accepted abbreviation for communist youth league.