I know I'm a bit behind the times on DA but what are widgets and where do they come from? Where can I get them etc.

I found my DeviantID has been upgraded and I personally at the time like it the way it was with out any of the dropdowns or picture. What will happen if I remove the current DeviantID? Will my profile go back to the way it was before? And if I change my mind later and want the new ID where can I get it if I remove it? I ask all this cause I can seem to find a link to a widget storage or where ever widgets can be obtained.