i have a blog with many pages/posts. sometimes i see two of my posts on first page in google?

[Mark]

and sometimes i can't find them even though i go through the first five pages of the internet.
i mean, i write in the search engine, and there one or two of my blog posts show up on first page, and sometimes not. and sometimes one of my posts shows on first page in google while the other cant be found in the first pages, and then they switch! the one that couldnt be found is on first page in google and the one that was on first page cant be found in the first five pages. maybe it went to page number fifteen or something...
what is causing this?

[Prashant Kumar]

Because google in not indexing in your url. Did you Complete onpage in your website. or you ever use Offpage? sometimes in your content indexing the google. Google update his algorithem that why your page are sometimes show 1 page or nothing.

If you want more about SEO contact me at prashant.chd04@gmail.com