In the actual binary system, the comparison works like so:
(Where the accepted standard is that capital B refers to bytes, but lowercase b is bits)
(The same in theory holds true where for example K refers to 1024, but k refers to 1000)
1 B = 8 b
1 KB = 1024 B
1 MB = 1024 KB
1 GB = 1024 MB
1 TB = 1024 GB
Now… When talking speed, they refer to what I like to call "Chinese Bytes", which breaks it down a little farther. Speed is measured in mb, not MB, so it's important to know how to factor to get it back to the scale as above. To do this, you break it down as follows (basing it on a 6mb/s line)
(6 mb) x (1,000,000 b/mb) = 6,000,000 b
(6,000,000 b) / (8 b/B) = 750,000 B
(750,000 B) / (1024 B/KB) = 732.42 KB
_Now… If this number were greater than 1024, you would divide again by 1024 to break it down into MB instead of KB... Again, if after dividing by 1024 to measure in MB is still above 1024, then you would divide again to give you TB.
I know it may seem confusing that hard drive space and internet data transfer speeds are measured in different units that would appear to be the same, however this is not the case. You do get used to it in time though._