Long Tail Pro is a keyword research and SEO tool that allows users to analyze keywords, compare links to competitors, and check ranking across search engines and countries. It provides features like suggesting related keywords from seed terms, comparing metrics like page rank and domain authority between links, and showing exact search results. The review demonstrates how to use the keyword research, competition analysis, and rank checker tools to analyze keywords related to "Long Tail Pro Review" and check rankings for a domain across search engines and global locations.