A website is not one legal object but a stack of overlapping regimes, and this UpLaw guide maps every layer that a modern online business has to stand on. It explains when an online contract actually binds — the reasonable-notice standard that separates enforceable clickwrap and sign-in-wrap from unenforceable browsewrap after Specht, Nguyen, and Meyer — and how to draft terms of service, arbitration clauses, and change-of-terms provisions that survive challenge. It then walks the immunities and their edges: what Section 230 covers and what Roommates.com, product-design claims, and the intellectual-property and FOSTA carve-outs pull back out, and how the DMCA's four safe harbors, repeat-infringer policies, and notice-and-takedown machinery actually work alongside Section 1201's anticircumvention rules. It covers trademark online (domains, the UDRP and ACPA, keyword advertising, and marketplace liability), the Computer Fraud and Abuse Act after Van Buren and scraping after hiQ, the tracking and consumer-privacy patchwork, advertising and email regulation, website accessibility under ADA Title III and the WCAG problem, personal jurisdiction over online conduct, defamation and anonymous-speech unmasking, and the evidentiary mechanics of proving what a web page said. A running hypothetical — the online marketplace Thistle Market, sued over a user listing, scraped by a competitor, and hit with an accessibility demand over its checkout — grounds each doctrine in a decision someone actually has to make.