Adverbs function as different kinds of definitions, usually for verbs ("Hon kör för fort"= She drives too fast) 
but also for adjectives ("Hur dum får man vara?" = How stupid can one be?) and sentences ("Hon lyckades tydligen..."= She obviously pulled it off).
An adverbial of time is a part of a sentence that describes a time for the situation described in the sentence. The most typical are sentences about something happening.

Hon åkte skridskor på kvällen. (She skated in the evening.)
Läkaren tog en paus efter operationen. (The doctor took a break after the operation.)
De simmar varje dag. (They are swimming every day.)

Examples of sentence adverbials:
möjligtviskanskeantagligen, lyckligtvisförhoppningsvis, alltsådessutomenligt

Adverbials of manner answer to questions: How? In what way? They describe the manner in which something is performed.

Katten jamar tyst. Hur jamar katten? Tyst! (The cat meows quietly. How does the cat meow? Quietly!)

Adverbials of space indicate the place for the expressed situation and often also include adverbials that are associated with motion.

Hon åkte skridskor på isen där på isen (She skated on the ice.)
Jorden kretsar runt Solen (Earth is rotating around the Sun.)