you can find in many sources this statement regarding LZ77 and LZ78.
They are both theoretically dictionary coders. LZ77 maintains a sliding window during compression. This was equivalent to the explicit dictionary constructed by LZ78 however, they are only equivalent when the entire data is intended to be decompressed.
I have difficulties understanding this, in the text mentioned, equivalency of an LZ77 to LZ78 (explicit dictionary). Could anybody explain it?