What is meaning of 'Blocking' in Firebug Net Panel?

Question

I\'m using Firebug 1.5.2 and while testing a site before production release i can see a huge amount of time consumed by \'Blocking\' parts of the requests.

What exa

Answer 1

As far as I know, two reasons cause components to cause blocking others from loading.

1. Browser's enforced (but usually configurable) limit of how many parallel resources can be loaded from a particular host at a time.
2. Inline javascript, which can cause the browser to wait and see if it at all needs to go ahead with downloading the rest of the components (just in case the javascript redirects or replaces the content of the page)