H.261 is a video compression standard developed by the International Telecommunication Union (ITU) in the early 1990s. It was designed primarily for low-bitrate video conferencing and is one of the first standards to enable efficient video transmission over networks. H.261 compresses video by reducing redundant data, allowing for smoother streaming even on limited bandwidth. The standard supports various resolutions, including CIF (Common Intermediate Format) and QCIF (Quarter CIF), making it versatile for different applications. Although newer standards like H.264 and H.265 have since emerged, H.261 laid the groundwork for video coding and remains relevant in specific legacy systems.