[Digital Today reporter Choi Jae-won (최재원)] Why do the speed shown on an internet plan and the actual file download speed appear different? The commonly used terms "Mbps" and "MB/s" may look similar, but they are different units of data transfer. Understanding the difference helps calculate internet speed and file download time accurately.

According to the IT outlet Engadget on Oct. 11 (local time), Mbps means megabits per second and MB/s means megabytes per second. The key distinction is the difference between bits and bytes.

A bit is the smallest unit used by a computer to process information, expressed as 0 or 1. A byte is a unit made up of 8 bits. Therefore, 1 MB/s is the same transfer rate as 8 Mbps. In notation, a lowercase "b" means bits and an uppercase "B" means bytes.

Mbps is mainly used to indicate download and upload speeds of internet lines. The U.S. Federal Communications Commission (FCC) sets the standard for high-speed broadband internet at 100 Mbps download and 20 Mbps upload.

According to internet speed measurement company Ookla, the median U.S. fixed broadband download speed in August was about 307 Mbps and the upload speed was about 64 Mbps. Compared with the FCC's 2015 download benchmark of 25 Mbps, the benchmark itself has risen fourfold.

MB/s, by contrast, is mainly used to describe file downloads or data transfer speeds between storage devices. Used together with MB and GB, which indicate the size of photos, videos and game files, it can help calculate the time required for transfer.

Unit conversion is simple. To convert Mbps to MB/s, divide by 8, and to convert MB/s to Mbps, multiply by 8. For example, a 100 Mbps internet connection can theoretically transfer 12.5 MB per second.

Actual download speeds vary depending on server performance, network congestion and the WiFi environment. Simple unit conversion and real transfer performance should be distinguished.