will connecting a wirless router slow down internet speed?

if i connect the ethernet cable from my cable modem to my netgear wireless router and then connect a ethernet cable from the router to my mac will it slow down my internet on my mac? and if it does is it by a lot?

also if it slows down should i just use wifi instead?

Well, the odds are that if a cable goes from your cable modem to a router then to your mac, yes, it will be slightly slower than it would if you plugged the cable modem directly into the mac. There is a slight amount of processing in a router. However, you would most likely never notice a difference.

It is, however, usually quite a bit faster to use a wire to the router than wifi, and more stable/reliable. But any of this really depends on your individual situation.

Here is more discussion on cable being faster than wireless:-

http://forums.macrumors.com/archive/index.php/t-152551.html