Arpeggio has two related meanings.
Literally, it means "like a harp", implying spreading a chord so you hear each note; most likely ascending but sometimes descending.
The other meaning, which applies more to improvisation, is the notes of a chord in any order, and in any octave, wherever you can find them on your instrument.
Because most jazz soloing is based on chord tones, knowing all the notes of every chord, everywhere, is obviously fundamental knowledge.
Nevertheless it would be rare to use arpeggios alone when soloing, unless perhaps the chords were changing fast. Generally the arpeggios would be your foundation, linked by passing notes and chromatics.
For any tune you want to improvise on, I suggest making sure you know the arpeggios of all the chords first, all over your instrument.