CDMA 1700 is a mode, which in this context means a combination of a technology and a frequency band. In this case, it is CDMA technology and the AWS frequency band.
The AWS frequency band has two parts, one near 1700 MHz and another near 2100 MHz. To avoid confusion with Europe's (quite different) "2100" band, Phone Scoop refers to AWS simply by the 1700 part, hence "CDMA 1700".
Note that this is completely US-centric terminology. South Korea also has a frequency band at 1700 MHz, that is different from AWS. Therefore Korean "CDMA 1700" phones are different than US "CDMA 1700" phones. Korean CDMA 1700 phones are not compatible with US CDMA 1700 networks, nor vice-versa.
It is important to not confuse CDMA with WCDMA.