H.265, or HEVC, is the successor to H.264. It compresses more efficiently, so a stream can hold its quality at a lower bitrate or carry more resolution at the same bitrate. The cost is heavier processing and less universal support across recorders, browsers and older viewing clients.
H.265 looks attractive on a storage spreadsheet, but the saving only exists if every device in the chain decodes it. Check the recorder and the operator software before standardizing on it.
Why H.265 saves bandwidth
The standard uses larger coding blocks and better motion prediction, so it describes the same scene with fewer bits. Savings vary with the scene, and heavy motion erodes them.
Compatibility is the real decision
Cameras, recorders, mobile apps and workstations must all decode the stream. Where a site mixes old and new hardware, H.264 on shared channels avoids black video.
Related:Commercial security camera systemsGlossary: Video management system