Where would you find this sentence in an essay?
my favorite memory is the time i went to visit my grandparents during summer vacation.

The sentence My favorite memory is the time I went to visit my grandparents during summer vacation would be in the introduction of an essay.

Explanation:

An effective essay is made up of three major parts: the introduction, the body and the conclusion. The first section aims to present the topic to the reader, give a hint of what the reader is going to find out and the overarching point, if there is a thesis statement. Then, the sentence My favorite memory is the time I went to visit my grandparents during summer vacation -as it serves to these ends- would be part of the introduction of a narrative essay, that is the one that tells a story.

its structered sequentially i think