What's the difference between the normal Mac Mini and Mac Mini Server? I'm planning to buy a Mac mini i5 as it's fitting my budget. 
Will be making it a server for hosting websites, so before I buy the i5 version I wanted to know if there is any hardware difference between the mini &amp; mini server.
Hardware difference as in working of the motherboard or any thing added extra. 

i will be upgrading the mini with 16GB RAM &amp; an SSD
There is no Mac Mini Server with an i5 processor, and with your upgrades, the Mac Mini with OS X Server has no hardware differences from the normal i7 Mac Mini. Unless you want 2 internal SSDs, you would be wasting $200. I assume that if you're hosting other websites then you would be using external Thunderbolt or USB drives for storage space, so it would make sense just to have the 256GB SSD.