Angular is a popular open-source JavaScript framework developed by Google that is used to build dynamic and interactive web applications. It provides a comprehensive set of tools and features for building complex web applications with a modular architecture, data binding, dependency injection, and more.
As with other JavaScript powered sites there are many things you can do to ensure they are SEO friendly. Many people will opt to make use of sever-side rendering or pre-rendering to generate HTML pages on the server side that then get indexed by search engines. Another option is to make use of dynamic rendering, or use the Angular Universal module to create server-side rendered pages.