Transmission speed, often referred to as data transfer rate or bandwidth, is the rate at which data is transmitted from one point to another in a communication system or network. It is typically measured in bits per second (bps) or a multiple thereof, such as kilobits per second (Kbps), megabits per second (Mbps), or gigabits per second (Gbps). The transmission speed determines how quickly data can be sent and received over a network or communication channel.

Higher transmission speeds allow for faster data transfers, which is crucial for various applications like internet browsing, streaming video, online gaming, and large file downloads. The choice of transmission speed depends on the specific requirements of the communication system or the capabilities of the network infrastructure in use.