The definitions of each term are as follows:

Embedded Object An embedded object is created in a spearate source file and then inserted into a destination file and becomes part of that file. If the original source file is changed in any way, these revisions will not update in the destination file.

Linked Object A linked object is created and stored in a separate source file and then linked to a destination file. If the source file is changed in any way, these revisions update automatically in the destination file.

How does this information relate to the artwork you receive?

Here is an example: Your artwork contains a logo that has been placed into an illustrator file and text has been added.

If the logo has been placed as a linked file, there will be an error message saying that a file is missing when you open it  on your PC or Mac. This is because the logo file is resident on the machine that the artwork was created on and not on yours. The destination file automatically looks for its associated links when it is opened.

In summary, embedding the image means that the file does not rely on link information and is completely unreliant on source files. It can be opened on other PCs and Macs without the occurrence of an error message.

How to tell whether the image is embedded or linked

Using the selection tool, click on the image. The bounding box for a linked file has two diagonal lines which cross in the middle. Embedded files have an empty bounding box. See the diagram below (the bounding boxes are shown in light blue).