|Interface in Firefox Browser|
|Select the are and click inspect element|
Use your Browser.
Almost every browser provide this feature.Still if you need more advanced features you can use an Extension like Firebug. All you need to do is selecting the area you want to check and right click and select inspect element from the menu you get! you may come with following interfaces like follows!
|Interface in Chrome.|
Use this to Web Development
There you can check the site style settings and structure when you go through the codes!.This tool comes handy when you are a developer and you need to edit and style your site you can check your site from here and you can apply your codes here or change the values on CSS attributes and check how will it affect your site.without editing your source and after check the appropriate settings you can add the code/changed values to the original source!
Use it in learning purpose
And this also comes handy when you want to study the structure of a other site and see what are the setting or attributes they have used to style their pages.Why not use this and learn some CSS tags! 🙂
Some Extra Info!