HTML frames are treated as independent pages, which is not a good web design practice. In fact, in HTML5, the <frame> tag was deprecated. As a result, few modern websites use frames nowadays. However, there are quite a number of sites that use iFrames. iFrames (inline frames) are a HTML document embedded in another HTML document (hence, inline). You can think of them as pages within a page.
In the context of automated testing, frames and iFrames are the same. In this book, we’ll use the terms frames and iFrames interchangeably.