my router gave me option to configure two wifi on different freqs, so I created one by the name "tousecontactxxxxxx" lets see who will knock the door

This is common among most routers. One should be 2.4GHz (it'll normally reach further but not be as "strong" of a frequency as the other but is more-or-less considered the default frequency), and the other should be 5GHz which has a number of benefits including less crowded frequency, "stronger" than the other as long as you are near the AP, etc. The only cons would be distance and maybe some compatibility issues with some devices.