Network is a noun and a verb.
Network is a noun, the collection of persons, places and things that we know about (or should get to know) that may have ideas on how we find employment. Examples of “a network” are our past employers, friends, relatives, fellow bus-riders, tennis partners, members of our church, the guy across the table at bingo, etc.
Network is a verb that describes how we expand our collection of persons, places and things that will eventually lead us to employment. Examples of “networking” are joining job boards, social media, talking to everyone about needing a job and informational interviews.