Cant seem find anything in forums :/
As topic says, im curious of what exactly is the difference between those cables ?
For example MPPS and Kline, they seem to be doing same things ?

The problem is Deko mixed several layers of transport protocols with products using them (once again hardware is mixed with software).
So K-Line is diagnostic line used to interface with control units, just as CAN bus for newer cars.
KKL is just a type of interface using K&L lines.
Then you have different hardware (HEX-USB/HEX-CAN and many others made by Ross-Tech to use with VCDS software, MPPS to be used with MPPS flashing software, Galletto, Kess V2, CMD, Byteshooter and so on each made to work with dedicated software). Some of them are talking only over K-Line, some only over CAN and some can use both. There are even interfaces which have multiplexer built in so they can switch pins they are using.
Here comes software part - most of the time each software works only with its dedicated hardware. Sometime the difference between interfaces is just custom programmed EEPROM in FTDI, sometimes there are other microcontrollers used.