COLS attribute means that these frames will be laid out in columns. The value of COLS, in this case, is the width of the columns in pixels. The NAME attribute allows us to access the frame through the object hierarchy. Advantages Keeps navigation tools from scrolling away. The photo gallery is a nice example.
Disadvantages Done badly, they complicate design.
Many pages are not intended to be framed. Frames break the history mechanism. They break the bookmark mechanism. Search engines may not index them properly. By breaking a page into several files, they make page maintenance a little more difficult.