[PsYcHo_RaGE]

first of all you ask too much and that confuses me alot much nvm

I assume the arc.ini has the COMMANDS/OPERATIONS for these tools, then the batch file is used to call arc.exe which carries out the compression using those tools & commands specified in arc.ini?
Ans: you are right

This, the CLS things...what is it ? i assumed its used when using Inno setup, but i plan on using traditional batch file.

what does cls means ? i know what is srep.
Ans: basically this is generated by a program called cls generator which you can find by searching it, so how they are doing it first of all get the srep.exe and put in cls gen and it will generate the specific .dll if i am right!

how ? basically it should be only the executable (cz thats what i've been doing for years
eg. i compressed files in archive 'data.arc'
so my batch will have
Ans: yes you can use the arc.exe also but sometimes it sucks and better to use .dll instead
and whatever you have been doing that time is right but somehow changed a bit and you need to change with it.

Are you implying all the method you mention is used in inno setup ? like you pack with compression tools then tie it together with inno and while decompressing inno can just use libraries (dll) not the exe's ?
Ans: mostly when we repack a game......let me explain it to you
e.g when you repack a file using srep+lolz only you implement these files lolz.exe and srep.exe but when you want to unpack them you either can use the same or use the .dll or both of em but they must have certain code to decompress it