Bitcoin Halving - What is it? How is it calculated? Does it affect my bitcoin balance? I have read a lot about the halving that is set to take place later this year, but my question is how is halving calculated? Will it also effect my bitcoin balance as a whole?
The halving takes place approximately every 4 years. It is programmed in the software.

It will not affect your current bitcoins at all. It only affects the newly mined bitcoins which will be 12.5 after the halving (instead of 25).

The halving is expected to influence the price of bitcoin. With less supply the price will probably rise given that demand is the same... at least in the long run, since supply could also stay the same or even increase if people that were holding bitcoins start to sell.