Wired + Wireless connection to Router

[#1]

I've connected to my router both with a cable and wirelessly. This seems to work ok but is there a downside to this arrangement? Which is actually used to connect to internet (or are both)?
If I disable either I can still browse internet.
Thank in advance.

[#2]

All is OK.
Neither wired or wireless connects to the internet - they both connect to the router.
The router connects to the internet (via the telephone cable).

[#3]

Thanks Crucibleofevil.
Perhaps what I should have asked is which connection is actually used to the router when this connects to the internet. Is it both, the fastest, the slowest etc.
I am concerned that the 'best' connection might not be being used.

[#4]

If your PC has a choice, wired is [almost] always fastest - but since wired and wireless are both faster than your internet connection, it isn't really important.
For gaming wireless will probably add 2-3 ms to your ping times...

[#5]

Unless you are like my daughter who gets in excess of 23Mbps on a speed test via a wired connection 

[#6]

I need to have a wireless connection for a wireless printer. Will it help my ping times if I also have a wired connection?

[#7]

Quote

I need to have a wireless connection for a wireless printer.

No you don't, your printer connects wirelessly to the router. Your PC communicates to the printer via the router, so even if you only have a wired connection to the router you will still be able to communicate with the printer.

[#8]

Most printers (in the home, anyway) are simply connected directly to a PC via a USB cable.

[#9]

MisterW is right of course - I don't need a wireless connection to the router  :-[.
The printer is a Canon MP620 (multifunctional device). I'm having issues with this at the moment in that connection is lost after 10 minutes or so, but that's another problem! I could connect via USB but I need to connect it wirelessly to my son's PC anyway.
Thanks everyone.

[#10]

You could have a wired connection from a PC to your printer, other PC's can make use of this connection on your local network to do their printing.
Of course the printer PC would have to be switched on for this work... 

[#11]

Quote from: Crucibleofevil

If your PC has a choice, wired is [almost] always fastest - but since wired and wireless are both faster than your internet connection

That might not be necessarily true if using ADSL2+ or cable connections and 802.11a/g wireless. The headline 802.11 rates are raw rates (eg no allowance for framing, preamble, CSMA/CA, IP or TCP overhead) in one direction only, and real-world throughputs will be much slower. I've known a single TCP stream to struggle to get near 8Mbps on 802.11g even with clear line-of-sight between client and AP. Any other networks in the area, or more than one client on the WLAN, or any number of other possible causes, can cause WLAN throughput performance to suffer.
And that's before you start considering things like poor USB adapter or device performance, and different 802.11 vendor implementations.
Basically if you want to make the best of a good ADSL2+ or cable connection and wireless, don't use 802.11g but move straight to proper dual-band 802.11n. Better still use a network cable which simply doesn't suffer from many of the things that affect wireless