It’s a little bit complicated, effectively, but the meaning is this:
“de l'” can be either an article partitif, like in this example:

“je veux de l’aide” (“I want some help”). Here, “de l’” is an article partitif , that might be translated by “some” (and even the word “some” may be omitted in English: “I want help”).

But here’s a second example:
“j’ai besoin de l’aide de Pierre” (I need Peter’s help). In this case, “de l’” doesn’t mean “some“, but “de” is here a required preposition because “avoir besoin” is not a transitive verb, so we must use “avoir besoin de“, and so “l'” here is independant