Bitcoin is different from Other Currency in numerous ways, some of which have been mentioned below:

Bitcoin has no central authority unlike other currencies which are backed by the government.
Bitcoin is subject to inflation alone due to scarcity caused by an artificial limit. Country backed currencies are subject to deflation as well.
Bitcoin transaction are registered in the Bitcoin blockchain which acts as a ledger whereas cash transactions may or may not be recorded.
Bitcoin transactions are immutable whereas majority of digital records can be duplicated.Bitcoin transaction require fees to be paid to miners which is quite similar to taxes that we pay to the government, except taxes can be evaded quite easily compared to having a transaction registered in the blockchain without paying fees.
Bitcoin transactions are made over the internet and are public where your addresses are known whereas cash transactions are pretty much anonymous.
Bitcoin is infamously also known as the internet’s currency for it is resident on the internet with scores of people (miners) keeping track of each transaction happening by recording it within the Blockchain.

Bitcoin is different is many ways from the normal currency that we’ve all been used to, but it is quite essential for our world to technologically advance in a progressive manner.