Bitcoin is a currency right?
Bitcoin is the first cryptocurrency, it is money and also an asset, appreciative asset.
How is it been produces?
Through mining. Miners are rewarded for mining a block while transactions are also included into the block for confirmation. At every 210000 blocks mined, the mining reward halve. The mining reward was 50 BTC before the 2012 halving, it halved to 25 after 2012 halving, it halved to 12.5 in 2016 having, it halved to 6.25 in 2020 halving and so on it would be at every 210000 blocks mined until all bitcoin are mined.
Does Bitcoin production mean Bitcoin mining?
Yes, the mining reward is bitcoin, which is how bitcoin is supplied into circulation.
If it does then what will be it's faith after the 21million mining limit...
Miners receive incentives also from transaction fee, the mining reward is reducing as I explained above, while more people are making use of bitcoin and also the price of bitcoin is increasing. Remaining less than 10% of bitcoin to be mined and yet the mining hashrate just reach all-time-high. Transaction fee will finally replace mining reward when all bitcoin are mined.