A sales pipeline is the organized view of all open opportunities and the stages they occupy on the way to closing. It shows how many deals exist, their value, and where each one stands. The pipeline is the foundation for forecasting revenue and spotting bottlenecks in the selling process.

Your pipeline is the most honest forecast you have if it is kept clean. Stale deals that should be dead inflate it and corrupt your planning. A real pipeline, weighted by stage and close probability, tells you what revenue is actually coming. Marketing's job is to keep it full enough to cover your number.

Example:

 A pipeline holds 40 open deals worth $2M total, spread across discovery, proposal, and negotiation stages, each weighted by its close probability to forecast revenue.

What is the difference between a pipeline and a forecast?

 The pipeline is all open opportunities. The forecast is the subset you realistically expect to close in a period, weighted by stage and probability.

How does marketing affect the sales pipeline?

 Marketing feeds the top of the pipeline with qualified opportunities. Without enough quality inflow, the pipeline thins and revenue targets become unreachable.