What's the meaning of "bootstrap"?

Bootstrap refers to a process that is akin to picking oneself up by the bootstraps. The idea is that it is physically impossible to lift yourself by bending over and trying to "lift".

Bootstrapping refers to doing exactly that but in a way analogous to physics. Computing is the most common area I hear the term. A program that bootstraps itself is one that begins with an extremely trivial operation and then uses that to continue the startup process internally. In a strict sense, the program does need help for the very first step but once that happens it doesn't need any external help.

This usage has expanded into less and less strict adherence to the physical notion of lifting and can now be used to refer to anything that is able to sustain itself without external support. My local dictionary defines it as such:

get (oneself or something) into or out of a situation using existing resources

start up (an enterprise), especially one based on the Internet, with minimal resources

This broadens the scope to include processes or situations that required a lot of help to get started. The focus is more on the idea of current autonomy. That being said, the origins of the term still place a tremendous emphasis on the beginning or start of the action.

Dictionary.com defines bootstrap (v) as:

–verb (used with object)
6. to help (oneself) without the aid of others: She spent years bootstrapping herself through college.

It likely derives from the idiom pull oneself up by one's bootstraps, which is a metaphor for succeeding in something using only your own resources.