What are the advantages and disadvantages of IFRAME?

1. Disadvantages
The biggest drawback of using frame structures in Web pages is that search engine "spider" Programs cannot interpret this page. You spend a lot of time, energy and money to open an online mall, but deliberately do not allow search engines to retrieve the mall, it is like opening a retail store, but the windows are painted black, but also do not hang any signs. The IFRAME blocks the onload event on the main page, the IFRAME and the main page share the connection pool, and the browser restricts the connection to the same domain, which can affect the parallel loading of the page, and these two drawbacks need to be considered before using the IFRAME. If you need to use an IFRAME, it is best to add the SRC attribute value dynamically to the IFRAME via JavaScript, which can bypass the two questions above.
2. Advantages
We can selectively let users view the site, do not need search engine crawling content, with ifame frame display, need to search engine crawling content without ifame frame display, so that can be very good to streamline the code.
IFrame can be the original page completely intact display, but, if used in the home page with IFrame, is undoubtedly self-suicidal road. Because once the Web page is covered by the IFRAME, your site even if you do a good job, also can not be ranked! If it is a Dynamic Web page, use the include is OK, but must remove its

What are the advantages and disadvantages of IFRAME?