What is a role of seed in (using SHA256) Pseudo Random Generator?

I understand how SHA256 work, and I think I know why we use seed for hash functions (SHA256), but I don't understand this notation:

DPRNG = H(1||seed)||H(2||seed)||...

Do they mean: apply SHA256 algorithm on first bits concatenated with seed, then concatenate it result of SHA256 of second portion of bits concatenated with seed and so on... ?

Thanks in advance :)