what does random seed value mean in weka? I use weka to make a dataset classification but there is an option in classifier evaluation ( random seed for XVAL/% split). What does this option mean? ,and what is the seed value ? ,and What is the effect of changing the value of this option from one to two or three or other values?.

I read that the value of the seed is the starting point, but what is the difference if it is the starting point(seed value) 1 or 2 or 10 , for example.
Seed is just a value by which you can fix the Random Numbers that are being generated in your task. Also, this is a general concept and not just for weka.

So, here random numbers are being used to split the data. Now if you run the code without fixing any seed, you will get different splits on every run. But if you fix the seed to some specific value, you will get the same split every time. This is useful when you want to make your scores reproducable.