Software is licensed, rented, built to order, embedded, and resold in a bewildering range of deals, and the law that governs them remains unusually unsettled. This overview maps every major deal type—on-premises licenses, SaaS and cloud subscriptions, custom development, and reseller, VAR, and OEM channels—and shows why the differences drive the analysis. It works through the threshold puzzle of which law applies (UCC Article 2 versus the common law, plus the cautionary failure of UCITA), how click-to-agree contracts form and bind, who owns code written to order, and how data, privacy, and open-source obligations travel through a transaction. Invented hypotheticals walk the negotiation of warranties, indemnities, liability caps, service levels, and escrow, including the modern cloud-continuity analog. It closes with M&A and asset-transfer traps, the disputes that actually erupt, an FAQ, and links to deeper UpLaw resources.