not me
What does this achievment mean ?

It just means you posted something in the main forums. You participated in the community.
But this is not my first topic and I have done lots of blogs

I haven't done 100 posts or blogs
Whenever you comment on another person's blog/post, it gives you a point. Points are just used to show how active you are in the community. The more points you have, the more posts you've made. It's not how many blogs/forums you've made, though that does count as a point. Anything you post counts. You're quote I used, this comment I'm making, and anything else you comment counts. The only type of message that doesn't count is in live chess. I'm not really sure if sending a personal message in someone in the Messages tab under the Home tab works, but if it does, that counts as a point, too.

If you look on your profile page you will see at the top a points section. You top 100 you get participant award. I think you get points for every comment you make on the forum. Not sure how else you get points though.
Kev

can anybody plz tell how to see anyothers achievements is it seen in one's profile or if not what is the point of these achievements if any one else cannot see them ??

I don't think your blogs have anything to do with the achievement award. The site is designed for participation.....blogs are an individual thing. Also, blogs have their own set of awards.
Posting a blog post is 1pt. Posting a note anywhere is 1pt. Posting a topic is maybe 10pts, or 1pt still. Posting on a topic is 1pt.
Today I got another achievement called participant and the only thing it said underneath was "you are part of the community!". Does anyone know what I did to get it?