Who is Efrayim the Matchmaker from Tevye the Dairyman and the Railroad Stories and what is their importance?

Efrayim the Matchmaker approaches Tevye on several occasions, meeting him in Boiberik and on the train while traveling. Efrayim offers Tevye many matches for his daughters, but only Beilke accepts the match with Podhotzur the contractor. Efrayim is having trouble doing business because more people are arranging their own marriages.