How long does KYC take?

I'm curious about the KYC process, could you shed some light on it? I've heard it's quite crucial in the realm of cryptocurrency and finance, but I'm not entirely sure about the specifics. Could you explain how long the KYC typically takes? Is it a quick and straightforward procedure, or does it involve a lengthier and more complex series of steps? Additionally, are there any factors that might influence the duration of the KYC, such as the exchange platform I'm using or the country I'm residing in? I'd appreciate any insights you could provide on this matter.