What is the strategy of forums posting ?

You need to understand what a backlink is for an answer to your question to have meaning to you.

Simply put, a backlink is your link whether through your direct url or an anchor text, placed on another website. You understand direct url i guess, i.e. http//www.moverspackersdelhincr(dot)com, while an anchor text is simply your keyword showing in place of your url (movers packers in delhi ncr) but the link still redirecting to your url.

If you get the above, then the 2 anchor text backlinks you have in your signature, under your text, are placed on a "Adsense / PPC / SEO Discussion Sub-Forum of the Warrior Forum" website's web page and is pointing to your website/page i.e backlinks
For it to be regarded as an effective backlink, we are talking of when it gets indexed by Google and other search engines i.e. when it features on their search engine result pages (SERP's).

When backlinks are placed on high activity/authority sites such as the warrior forum, they get indexed pretty fast(say a few days) but on less activity/authority sites, it may take longer to get indexed.