Question about Wheels

Hello,

I am a young and inspiring car entheuasist and I just joined the forum recently. I am looking for basic information to expand my knowlege within somewhat general car parts and accessores. With myself being into adding accessorest to enhance the look of my car, I have started with some chrome products and I have been looking at rims and wheels. I figured this would be the best place to get some help because by the looks of eveything, it seems eveyone on here is very knowlegeable. My first question is dealing with the rims themselves, I see many alternatives out there and i dont know why to pick one product from the next. What is the difference between alumimum and something called Chromtec. What are the disadvantages and advantages of both. With this being my next potential purchase, I want to ensure I am firmilar with everything.