Grammar terminology matters because it allows us to communicate efficiently about language. Of course, it is not necessary to know the terminology to speak a language. We all learn our first languages without first learning what a verb and noun are. However, when we speak about grammar, especially in the context of writing, it helps if we can refer to grammar using precise vocabulary.
There are many sources online and in books that will explain grammar terminology. Not all of them will use exactly the same terms for the same grammatical points (I know, frustrating!). However, if you get into the habit of learning to identify the names of grammatical objects, you will move forward in your understanding of written English.
Sites and books that you can use to look up the names of grammatical terms
- The Elements of Style http://bartleby.com/141/
- Using English: http://www.usingenglish.com/glossary/