Clickwrap
A contract formed by clicking "I agree" – the kind of online consent courts are most willing to enforce.
The name descends from shrinkwrap, where tearing the plastic off the box supposedly meant accepting the licence inside. Once software arrived by download, consent moved to a button in the installer, and later to the sign-up form. The legal test is the one that applies to any contract: the user must have had a reasonable chance to see the terms and must have done something that unambiguously means yes.
That is why the variants have fared so differently in US courts. Pure browsewrap, where the terms sit behind a link at the bottom of the page, lost in Specht v. Netscape (2002) and Nguyen v. Barnes & Noble (2014). Sign-in-wrap, with "by signing up you agree to our terms" printed next to the button, survived in Meyer v. Uber (2017). Nobody reading the text is beside the point. Nobody reads their lease either.