Wikipedia - https://en.wikipedia.org/wiki/Encapsulated_PostScript
Encapsulated PostScript (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. Simply, an EPS file is a PostScript program, saved as a single file that includes a low-resolution preview "encapsulated" inside of it, allowing some programs to display a preview on the screen.
EPS or Encapsulated PostScript is a standard graphics file format for exchanging illustrations, logos, images, designs, drawings or even layouts of complete pages. An EPS file internally contains a description of such an object or layout using the PostScript page description language. It can include both bitmap and vector data.
An EPS file can contain any combination of text, graphics, and images. Since it is actually a PostScript file, it is one of the most versatile file formats available. EPS files usually contain a small preview image that is used to visualize the content of the file. This is done so that applications don’t need a PostScript interpreter to display the content of the EPS file. Even office applications such as Microsoft Word can display the preview image. If an EPS file is sent to a printer that doesn’t support PostScript, it is once again this preview image that is printed. The quality will not equal that of the read EPS artwork but at least there is an image on the print-out.
EPS files are compatible with most vector programs such as Adobe Illustrator or Corel Draw. Vector illustrations will also open into many photo-editing programs such as Photoshop and can be saved as JPEGs, TIFFs, PDFs, or other raster file formats. They can also be imported into page layout programs like InDesign and Quark. If you are unable to open the file into a vector or raster program then a quick Google search regarding your specific software may help solve your problems, but if you continue to have problems please contact me and let me know which file format you require and I'll be happy to help and send an alternative file format if necessary.
My stock vector illustrations are saved as EPS files (along with high res jpegs), which I provide inside a ZIP folder for easy downloads. If you can't find the EPS file, it's probably still inside of a ZIP folder on your computer.
Some web browsers will automatically open downloaded ZIP files for you, but others will save the ZIP file directly to your computer. To access the EPS, double click on the ZIP file.
If you have problems opening the ZIP folder, try the following steps:
Check your browser's Download Manager to ensure the ZIP file has finished downloading to your computer.
If the folder won't open when you double click the ZIP file, try shortening the ZIP folder name to 8 characters or less.
If the ZIP folder has downloaded but won't open even after you've shortened the file name, you can always get in touch and I'll be happy to help and send an alternative file format if necessary.
If you've opened up your EPS in your vector program but are unable to edit the shapes in the file, try the following:
Ensure you've opened the file labeled 'EPS'
Open the EPS file into your editing software and open your 'Layer' palette. If you see a lock icon next to the layer, click on it to unlock the layer so that you can edit the shapes.
There's a lot more information available online if the above doesn't quite answer your questions. Try a little Google search regarding your specific problem and software options and you should hopefully find an answer. I am always happy to help if you'd like to discuss things directly with me or to request an alternative file format.