Say you had a memory part that had 20 address lines and had data 8 bits. That would be a 1 MegaByte part, 1 million address of 1 byte each.
If the same part had 16 data bits, it would be a Word wide, so 1 Megaword.
Now add some more address lines - 24 lines (16 Mega-address locations), and 16 bits, so 16 Megawords.
No datasheet, no progress.