Language development is conceived as relative to one's own past performance, or relative to that of others.
I do not understand these parts : is conceived as relative and that
I checked the dictionary.
"conceive" has different meanings: 1: to imagine a particular situation or to think about something in a particular way 2: to think of a new idea and develop it in your mind 3: to become pregnant
"Relative" has two meanings. 1: having a particular quality when compared with sth else 2: connected with a particular subject
But I am not exactly sure which meanings are correct in this context. Unfortunately , there are no other sentences to have an educated guess. Can somebody please help me out?