You are quite busy with lots of cool stuffs, yes we know! so I will make this really quick
Bandwidth is defined as a range within a band of frequencies or wavelengths. Bandwidth is also defined as the amount of data that can be transmitted in a fixed amount of time. For digital devices, the bandwidth is usually expressed in bits per second(bps) or bytes per second. For analog devices, the bandwidth is expressed in cycles per second, or Hertz (Hz).
The bandwidth is particularly important for I/O devices. For example, a fast disk drive can be hampered by a bus with a low bandwidth. This is the main reason that new buses, such as AGP, have been developed for the PC.
For example, when you connect to the Internet using a modem over a phone line, your operating system may display "Connected at 56 kbps." meaning a maximum of 56 kilobits of data is transferred every second. The more bandwidth a computer has, the faster it will be able to send and receive information. Users with a broadband connection, more specifically fiber optic broadband, can get transfers speeds of up to 10 Gbps, which is nearly 180,000 times faster than a 56kbps modem!
Note that bandwidth is not the only factor that affects network performance: There is also packet loss, latency and jitter, all of which degrade network throughput and make a link perform like one with lower bandwidth. A network path usually consists of a succession of links, each with its own bandwidth, so the end-to-end bandwidth is limited to the bandwidth of the lowest speed link (the bottleneck).
So I hope you now know that when you have superb upload and download you say you have a good bandwidth!