Transcribing in music is a term that sometimes refers to the process of notating music that has not been notated.
One reason musicians transcribe music is, it develops their ability to recognise specific musical patterns, combination of pitches and rhythms. The most common reason it is a way musicians can gain an insight into musical structures and patterns that build compositions. Musicians use these musical patterns, combination of pitches and rhythms to create their OWN music.
Using the recording of your improvisational solo, you will transcribe your improvisational solo in the notation software Finale.