People who have a new Rogers WiFi modem or those who purchase their own WiFi router often see that they have a choice of connecting by 2.4 GHz or 5 GHz. Quite often this will show up on your WiFi choices as yournetwork-2G or yournetwork-5G. The most common thing to think would be that 5 is better than 2 so obviously you'd choose 5. Unfortunately it's not that easy. There are several advantages to both of these, but to make things simple here are two rules of thumb to decide which one to use:

2.4 GHz moves data slightly slower, but it reaches further so you get a better signal the further way you are

5.0 GHz moves more data faster, but does not reach as far as 2.4GHz

Basically, if you are just doing the regular web surfing and checking email then 2.4 GHz would be the best since you wouldn't notice any speed difference and you get the best range. If you are doing something very data intensive like streaming movies or music, downloading large files or playing games online then 5.0 GHz would be better, but you will have to be closer to your router to get the best results.