Related Keywords report shows all search queries that are semantically associated with the researched keyword, i.e. they share at least two identical pages in Top 20 search results with your seed keyword.
Search Volume (1) — keyword’s monthly search volume;
CPC (2) — keyword’s cost-per-click according to Google AdWords;
Competition (3) — level of competition on the keyword in paid search;
Connection Strength (4) — the number of identical search results in Top 20 listings produced by the researched query and its related keyword. The highest value of connection strength equals 20.