Necessary to check page ranking in search engines

Do i have to check my ranking in search engines and how this can benefit me?

Always check your rankings in Search Engines because that is the only place where you can see which SEO effort are working and then you can modified accordingly.

If you know one of your website page is on second position in a Search Engine then you know your almost there you just have to see where you can improve this page to jump to number page number one in that particular search engine.