I just bought the truck on Friday, and noticed that sometimes when I turn the key to start the truck, I will hear a click sound and a second later the truck starts... is this normal?

 

I just started the truck a few times and it always started as usual... now I'm wondering if the 'click' is related to any of the numerous electronics in the dash; everything works, but this truck has so much electronics and gadgets, tough to tell exactly what it is or where it's coming from. It doesn't seem to be causing any problems, but was more curious to know exactly what it could be.