Specific words or phrases you type into search engines to find information. Like asking for directions by naming the specific place you want to go.
Typing 'best pizza near me' uses keywords to help search engines find local pizza restaurants.
Keywords are a general search and information-retrieval concept, not a specific cloud provider service. All major clouds use keywords in their consoles, documentation sites, and log/search tools, but the term itself is provider-agnostic.