You can see Bitcoin as an asset that you can hold or store for as long as you want. You can allow its price to rise, and then you can sell it for a margin. The same as you do for other assets, such as gold or real estate.
At the same time, there are digital marketplaces from where you can buy goods in exchange for Bitcoin. Here, the function of Bitcoin is that of a currency. However, some experts do not consider Bitcoin a currency as it is not a stable store of value and experiences high price swings and volatility.