You might come across SRS files when you download files from Usenet. For example, an NZB file containing a large video file may also include a smaller sample video. And along with that sample file there may also be an SRS file. However, you don’t need the SRS file to play the sample video, so most people can just throw them away.
SRS files are very similar to SRR files, so take a look at our SRR Files page for more information. The .srs file extension was first used by Microsoft Outlook. However, the SRS files that you find in NZB files are a completely different type of file.