The specific segment of the Total Addressable Market that a company can realistically target and serve given its current geography, channel capabilities, and product specialization.
Why it matters: SAM grounds the TAM in reality. It shows investors what portion of the market the startup's current product roadmap and go-to-market strategy can actually reach.
In practice: While the TAM might be all global restaurants, if your software is only in English and requires a specific point-of-sale system, your SAM is only English-speaking restaurants using that POS.