What are Bitcoin Faucets ?

Bitcoin faucets were developed by Gavin Andresen in 2010. Bitcoin faucets are a reward system, in the form of a website or app, that dispenses rewards in the form of a satoshi, which is a hundredth of a millionth BTC, for visitors to claim. These rewards are dispensed at various predetermined intervals of time. And can be claimed by either completing a captcha or task as described by the website. There are also faucets that dispense alternative cryptocurrencies.
Faucets usually give fractions of a bitcoiin called a satoshi, the amount will typically fluctuate according to the value of bitcoin. Typical payout per transaction is less than 1000 satoshi, although some faucets also have random larger rewards. To reduce mining fees, faucets normally save up these small individual payments in their own ledgers, which then add up to make a larger payment that is sent to a user's bitcoin address.
As bitcoin transactions are irreversible and there are many faucets, they have become targets for hackers stealing the bitcoins.