Which kind of forks exist?

• The soft fork.
  A soft fork is an update to the code which is fully backward compatible, similar to the usual upgrade of a lot of apps you use every day, you simply update and can still use data from not updated software.

• The hard fork.
  A hard fork is a code change which significantly changes the rules and is not backwards compatible, similar to e.g. an update of your office software which makes you unable to load documents written with the old version.

• The silent fork.
  A silent fork can happen every day, even multiple times a day, e.g. when ever two persons are staking the same block at almost the same time, it is a byproduct of distributed consensus and is resolved when subsequent blocks are added to one, making it the longest chain, while the other chain gets abandoned by the network, a silent fork is self healing e.g. by restarting the wallet.

Lately Gridcoin had some of these silent forks and some people paniced a little bit, that's why i wrote this little article.