Protractor is an open source functional testing framework for AngularJS applications. It automates interaction with AngularJS apps for end-to-end testing. Protractor uses Selenium WebDriver for browser control and Jasmine or Mocha for writing test cases. Tests are organized into pages, common utilities, test data, specs, and configuration files. Protractor provides locators and functions to test AngularJS apps and generates Allure reports for test results.