The vast majority of people will be under the impression that they are the same, but this is not the case. A search query, also known as a search phrase, is the actual word as well as a string of words that a user puts into the search box of a search engine (for example, "apple" and "with the sweetest flavour"). This may be in the form of sentences, queries, or even words that have been misspelled. Because more and more people are using voice search, people's searches are becoming longer and more specialized.
A "keyword" is a term or set of words that are very particular and may lead to variants or searches. The keyword "apple" is a very high-level keyword that can lead to a great number of different queries, such as "apple tree planting," "apple desserts," or even "apple computer." This last example emphasizes the need to look further than keywords and consider full queries, as a fruit and a MacBook are two very different things.