it could be used as both . for instance you can use it for transactions and you can also save it till the prices have risen then spend.
when i was trying explain to my dad i told him they were shares. the prices can drop and rise at any time. that when he want to withdraw(spend or covert to cash ) he can at any time . but its better as an investment cause later in the future it will cost more than the price you bought it .( it has its return on investment) till now my dad didn't get it he started saying the money can't be on the internet that its a scam. i don't blame him much we are Africans. we hardly believe things without tangible proof....