[quote=@BrokenPromise]
[@NekoMizu] I suggest you do some research on google about what people are discussing here. Particularly Steampunk and the stuff Aix was talking about. you don't need to read the entire wiki page, but it'll help you understand what a genre is. Steampunk is most certainly not future anything though, despite having technology that has never and will never be invented.

You also need to state what "the way you are thinking of" representing a "modern/future/past" world is. I've seen post-apocalyptic settings where it's the future, but due to resource shortages people rely on modern and old technology. Is that what you're talking about? 
[/quote]

I'm just thinking about a fantasy world that simply has future technology in some regards, modern technology in others, and medieval/past technology as well and it taking place in one of those eras. Most likely past or future. If we're talking about a mix of all three, anyway.

If we're talking about mix of modern and medieval I mean a fantasy world that takes place in a medieval type era, where swords and bows are the most prominent types of weapons (as well as magic), but has modern/semi-modern technology already set in the world, so not taken in by the main character like in Re:zero or No Game No Life. Think of like SAO or Log Horizon, but the game world has phones, computers, and other modern technology. 

I'll read about it to get a general idea of what steampunk is, yeah. Thank you for the suggestion.