What is the meaning of Alles?

everything

all

masculine/neuter genitive singular of al

totally; altogether

all told; in all

in some way; somehow; at all; after all

genitive of alle

alternative form of ealles

else

thoroughly

everything

yet, not before, still, quite recently, already

everything; all

all (as in "we all" etc.)

Used with an interrogative to express that the answer probably covers more than one item, like dialectal English all.

form of all

everything

Source: Wiktionary