I understand that ssh keys are a cryptographically secured way of authenticating yourself to a service or to another person, but beyond that I'm frankly at a bit of a loss.
What confuses me is that I see many developers mention their public key on their site, but how does one have just one key? I have a few for different things. And if my computer crashed, I would have to generate new ones. I obviously can't remember the key.
Do people just save it somewhere, the sequence of numbers/letters, like in their email? And then use that one key for everything? How does someone get a personal key?
I just feel like I'm missing something about this whole theater of operations.
I mean, we walked through RSA in university; I understand the principle, but I never used it in practice until I signed up for github and heroku and few months ago and they forced me to generate some keys, something I didn't even realize I could do before then.