A software license agreement is an organized answer to a sequence of questions, and once you learn the sequence you can read almost any of them. This guide starts with the load-bearing choice that shapes the entire document—software is licensed, not sold—and the copyright machinery (17 U.S.C. §§ 106, 109, 117) and case law (Vernor v. Autodesk) that make that choice matter. It then dissects the license grant clause by clause, maps the perpetual, subscription, and SaaS commercial models, and untangles the proprietary-versus-open-source divide. Separate sections work through online contract formation (clickwrap, browsewrap, sign-in wrap, and the ProCD-to-Nguyen line of cases), the interlocking risk clauses (warranties, IP indemnity, and the liability cap), and the quiet operational terms—maintenance and SLAs, source-code escrow, audit rights, assignment and change of control, and data and privacy—that decide real outcomes. It closes with a reader's decision tree, key takeaways, and a negotiation-focused FAQ, written so a founder, in-house lawyer, judge, or curious non-lawyer can all use it.