Pipeline is the inventory of in-flight deals. It's stage-segmented (discovery, demo, proposal, negotiation, closed-won/lost) and usually probability-weighted by stage. Pipeline coverage, total weighted pipeline divided by quarterly target, is the standard early-warning indicator for hitting a sales number.
The rule of thumb is 3 to 4× pipeline coverage entering a quarter. Below that, the team will miss; above 6× usually means deals aren't progressing and pipeline is stale.