How does tax law apply to cryptocurrency gains in different countries?

So, here's what I've been pondering lately: Been dabbling a bit with cryptocurrencies, you know, Bitcoin, Ethereum, the works; made some tidy profits too. But then it struck me - how does the Taxman treat these profits? Does it count as income? Capital gains, maybe? And what's even more intriguing, how do different countries handle this?
Like, are there places where HODLing is more tax-efficient than others? Or is it all just treated the same, globally? + If anyone's got any personal anecdotes or experiences with this, I'd love to hear 'em! Expert opinions are cool too! On a mission to demystify this whole crypto taxation business. Help a fellow out, won't you?