The major difference between GSM and CDMA is GSM uses Time Division Multiple access to simply each local network allocated time slice of cycles where it" owns" its bandwidth..So it used to send or receive data...In CDMA its different ituses Code Division Multiple Access....So this differs how to break the time of slice in cycles.
GSM have an exterior sim card while CDMA have an inbuilt sim card.
GSM- it is connection less system. CDMA- it is connection oriented system
The CDMA network operates in the frequency spectrum of CDMA 850 MHz and 1900 MHz while the GSM network operates in the frequency spectrum of GSM 850 MHz and 1900 MHz.
CDMA has faster data rate as compared to GSM as EVDO data transfer technology is used in CDMA which offers a maximum download speed of 2 mbps. EVDO ready mobile phones are required to use this technology.
GSM uses EDGE data transfer technology that has a maximum download speed of 384 kbps which is slower as compared to CDMA. For browsing the web, to watch videos and to download music, CDMA is better choice as compared to GSM. So CDMA is known to cover more area with fewer towers.