Adaptive Bitrate Streaming (ABR) is a method of streaming audio and video over the internet in which the quality of the stream is adjusted automatically based on the available bandwidth and network conditions. In ABR, the streaming server maintains multiple versions of the audio or video content at different bit rates, and the client software selects the appropriate version to stream based on the current network conditions. This allows the stream to be played smoothly, without interruptions or stuttering, even if the available bandwidth or network conditions change during playback. ABR is often used for streaming video over the internet, and is supported by many popular streaming platforms and video formats, including HLS and DASH.