Bitcoin is easiest to call a kind of hybrid asset with an evolving legal framework. Digital mode: features, decentralized nature, anonymity, high transaction speed, reliability, lack of regulators. If to look practically, today bitcoin is used mainly as an investment, even rather a speculative asset. One can observe attempts to create its currency functionality, but so far this format of using crypto currency has not gained much popularity, since its price is too unstable. As the preservation of the cost of bitcoin, and even today it is impossible to use.
It is highly being used nowadays and there are some services and famous stores that accepts BTC now. When we are going to base its transaction rate and speed, then BTC is an asset, I wont buy a candy with BTC and a very high fee, its not worth it, but it can be a reserve like oil and gold. BTC is good for banks and companies that transacts a large money, BTC can be used by trasactions like that, one click then it is on another wallet, unlike banks travelling money in a armoured car is pretty expensive. And like gold BTC have other kind like currencies that can do its part in everyday transactions like Eth.