Python random state in splitting dataset

I'm kind of new to python. can anyone tell me why we set random state to zero in splitting train and test set.

X_train, X_test, y_train, y_test = \ train_test_split(X, y, test_size=0.30, random_state=0)

i have seen situations like this where random state is set to one!

X_train, X_test, y_train, y_test = \ train_test_split(X, y, test_size=0.30, random_state=1)

what is the consequence of this random state in cross validation as well?