Employee referral
An internal recommendation from someone at the company, which routes your application to a reviewed queue instead of the general pile.
A referral's value is nearly all in guaranteed human review. Referred applications are typically flagged in the ATS and looked at by a person, which is the exact step that most applications never reach. It doesn't get you an offer and doesn't survive a bad interview, but it converts a lottery into a reading.
Referrals from people who can say something specific are worth much more than referrals from people who can't. "I worked with them for two years and would hire them again" and "someone from my university asked me to submit this" enter the same queue with very different weight — and most referral forms ask the referrer how well they know you.
Which makes the sequencing obvious: build the relationship before you need the referral. Asking a near-stranger to vouch for you puts them in an awkward position and produces the weak version. A conversation first, an ask second, works.
Informational interview
A short, low-stakes conversation with someone doing the work you want, asked for as research rather than as a job request.
Recruiter screen
The first conversation in most hiring processes — a 20–30 minute call confirming basics and deciding whether to pass you to the hiring manager.
Pipeline
All the opportunities you have in progress at once, seen as a funnel from application through offer.