through; throughout; by way of; via
Used after a noun to indicate a medium, period, or intermediary. Can mean 'throughout a period', 'via a person or method', or 'through a place/medium'.
He kept jogging every day throughout the year.
You can connect with people all over the world through the internet.
I sent my resume to that company through my senior colleague.
に渡って focuses on the extent or duration something spans, while を通して can mean the same but also commonly means 'via/by means of' a channel or person.
Phrase consisting of the object marker を and the te-form of the verb 通す (to let pass, to put through). Literally 'letting (something) pass through', it grammaticalized into a postposition meaning 'through' or 'via'.