Every posting on SAM.gov carries a notice type, and the type is the single fastest signal of what the government actually wants from you right now. Here they are in the order they usually appear.

Sources sought

Market research, before any contract exists. The agency is asking "who out there can do this?" and your answer is a short capability write-up, not a bid. This is the earliest and cheapest place to matter: if enough small businesses respond, the agency may set the eventual competition aside for small business, which shrinks your future field of competitors. Responding also puts your name in front of the buyer before there is anything to win.

A sources sought is not a promise that a contract will follow. Some never do.

Presolicitation

A heads-up that a solicitation is coming. There is usually nothing to submit yet. The useful move is preparation: read it, decide whether you would bid, and watch for the real thing. Presolicitations often carry the eventual NAICS code and set-aside status, which is enough to know whether it is worth tracking.

Solicitation

The real ask. The agency wants bids or proposals, and the notice carries or links the full requirements, the evaluation rules, and the deadline. You will see a few flavors:

• RFP, request for proposals. You submit a written proposal; the agency can evaluate on more than price and may negotiate.
• RFQ, request for quotations. Price-forward, usually for simpler or smaller buys.
• IFB, invitation for bid. Sealed bidding. The lowest responsive price wins, no negotiation.

The flavor changes how much writing you do and how much price decides the outcome.

Combined synopsis and solicitation

The announcement and the solicitation in one posting, common for straightforward commercial purchases. There is no separate heads-up coming; the clock is already running when you first see it. These often have shorter response windows, so they reward whoever is actually watching.

Award

The competition is over and this is the receipt: who won and usually for how much. Not a chance to bid, but far from useless. Award notices tell you what agencies pay for work like yours, who your competitors are, and when that contract will come around again.