Encapsulated PostScript, or EPS, is a DSC-conforming PostScript document with additional restrictions which is intended to be usable as a graphics file format. In other words, EPS files are more or less self-contained, reasonably predictable PostScript documents that describe an image or drawing and can be placed within another PostScript document.
At minimum, an EPS file contains a BoundingBox DSC comment, describing the rectangle containing the image described by the EPS file. Applications can use this information to lay out the page, even if they are unable to directly render the PostScript inside.
EPS, together with DSC’s Open Structuring Conventions, form the basis of early versions of the Adobe Illustrator Artwork file format.