Here is a summary of the difference that I know of:
4S: you know it, the bread and butter that has glass and stainless steel body, HSPA / EVDO baseband (so call 4G in the US).
5: LTE baseband, faster processor than 4S, longer HD screen, slightly lighter and thinner, anodize aluminum shell that is easier to scratch but thinner and lighter.
5C: same as 5 except a plastic shell, same price (but they discontinued the 5 so you are forced to buy a 5C).
5S: faster processor than 5, a sturdier metal shell (I think it is either a stronger anodize aluminum or a "liquid metal" (zirconium alloy) coating, finger print sensor, a champagne color option.
The baseband is the same between 5/5C/5S
4S: you know it, the bread and butter that has glass and stainless steel body, HSPA / EVDO baseband (so call 4G in the US).
5: LTE baseband, faster processor than 4S, longer HD screen, slightly lighter and thinner, anodize aluminum shell that is easier to scratch but thinner and lighter.
5C: same as 5 except a plastic shell, same price (but they discontinued the 5 so you are forced to buy a 5C).
5S: faster processor than 5, a sturdier metal shell (I think it is either a stronger anodize aluminum or a "liquid metal" (zirconium alloy) coating, finger print sensor, a champagne color option.
The baseband is the same between 5/5C/5S