What is mining means?
https://www.webopedia.com/TERM/C/cryptocurrency-mining.htmlWhat is proofs of stake
Mining is Proof of Work (PoW) while staking/proof of stake (PoS) is you hold a certain amount of coin and you get to mine through holding that amount, you will also get rewarded for that. It's almost the same as masternodes but they have difference. ETH is about to change from PoW to PoS soon.
And can I mine in my android or I need special types of desktop, laptop or mobile?
There are some claims that allows you to mine through mobile but it's not advisable, the same goes for laptop. What you need when you mine is you need a specific machine called ANTMINER that's dedicated to mine bitcoin and few specific altcoins. But if you love to mine altcoins, you can do it with GPUs.
Do I need some amount of mine-able coin for mining?
You need a capital for the hardware.