The most effective way to use the tool from experience when trying to find keyword popularity for SEO is to type in the keyword and sort by 'Exact' which is when people type that phrase in that order with nothing else. That gives you the most accurate assessment of the popularity of the word, where as broad is when the words are "somewhere" in the search box. Thought that might help some newer SEO's
Yes that's correct but using the synonyms and the keyword suggestion sections too are very great and helpful. Please note that people use a variety of terms for searching.