What is bandwidth?

Bandwidth explained

The definition of bandwidth, in regards to broadband Internet, is the highest amount of data that can pass through the data lines and modem in a specified time period. 

That amount of data is typically calculated in bits (or bytes) per second. The larger the number, the more amount of data that can pass through.

Sometimes, there will be two different numbers associated with bandwidth. Inbound bandwidth is in regards to how much data your computer can receive in any give amount of time, while outbound bandwidth has to do with how much data can be transferred from your computer to the Internet in a specified time period.

For basic Internet activity (surfing the Web, sending email, etc.), inbound bandwidth is the more important feature.