If you're doing research and preparing to publish, or already have published works to your name, a Google Scholar profile allows you to customize and showcase publications and how many citations they've received. Google Scholar will then calculate a platform-dependent h-index for you. This profile will also make you more "googleable" across all Google searches and increase your scholarly SEO (search engine optimization).
Google Scholar does not contain all scholarly material ever published or created so your Google Scholar profile and resulting citation metrics represent a certain section of literature that is indexed by Google Scholar. The quality of Google Scholar citations has been questioned and specifically challenged for inflating citation counts. For instance, it is likely a scholar's h-index in Google Scholar is much higher than in a competing citation index by competitors like Scopus and Web of Science. Some scholars claim that Google Scholar is easily duped by "fake" or predatory scholarly publications.
Google Scholar's algorithm is proprietary so we cannot know exactly how it returns the search results that it does. However, researchers have attempted to reverse-engineer the algorithm and at least one article concludes,
"Citation counts is the highest weighed factor in Google Scholar’s ranking algorithm. Therefore, highly cited articles are found significantly more often in higher positions than articles that have been cited less often. As a consequence, Google Scholar seems to be more suitable for finding standard literature than gems or articles by authors advancing a new or different view from the mainstream."
Keep this in mind when you select Google Scholar to research literature in your discipline.
"Google prefers algorithms over humans, and at this time, it is still very easy to trick an indexing software to think you’ve created an original scholarly document. Moreover, there is no reason why Google, unlike Thomson Reuters, would want to invest huge amount of human resources into fixing their citation indexing problem. Google is in the business of selling advertisements to companies, not metrics to scientific organizations."
Davis, P. (2012, December 12). Gaming Google Scholar citations, Made simple and easy. The Scholarly Kitchen. https://scholarlykitchen.sspnet.org/2012/12/12/gaming-google-scholar-citations-made-simple-and-easy/