Object linking and embedding (OLE) refers to the practice of providing a link in a document directly to a source of data or a graphic or embedding that data or graphic in the document itself. OLE's features make it a convenient tool for those creating documents or presentations that need to be kept up to date, but it has some downsides as well.
You can maintain control over the source through object linking. The link goes back to information that you can control, so you can quickly and conveniently update the information or graphic without needing to point the user to a new source. A person can go back and revisit the link over and over again to get the new information.
An embedded file can be quite convenient for users of the presentation or document, as they will be able to view the file or graphic right in the document without having to click through a link or follow a web address, which may require the user to log in first or jump through other hurdles.
All users have to have access to the file and the application that runs it, which may prove to be a disadvantage if you have people who need to access the link who don't have the right permissions or who aren't able to install the correct program. In that case, your presentation or document is only as good as the privileges or software that your users have. This is not as big of a problem if you have a lot of users who are on the same network or work in the same office.
An embedded file will show up as just a snapshot or it won't be displayed at all if a user can't obtain access to the file. This can derail a critical presentation or document that depends on the information you are embedding within it. You may have to test the embed from the systems that will need to reach it to ensure that it works, which may take a lot of time to do.