Keyword is what advertisers target in Google ads account. Searchterm is a word / phrase users search on Google. Google ads provides a list of searchterms match with keywords in the respective account to which ads were shown / clicked / converted or all. Analyzing searchterms would help understand the relevancy of keyword targeting.

Keywords can be paused or bids can be increased if a keyword is resulting in relevant & profitable searchterms.

Searchterms can be added as negatives in broad, exact & phrase match types, if they're found to be irrelevant.