They are from Tanenbaum network book:
Bandwidth is the capacity of the media in bits/sec
Bandwidth is the width of the frequency band, measured in Hz
I believe that CS stands for Computer Science, and EE stands for Electrical Engineering.
What it means is that electrical engineering looks at the physical circuit properties, while computer science looks at the practical application of moving bits. The number of bits can be more, less, or the same as the frequency in Hz, depending on several things, e.g. encoding.