If you are talking about weights and the US vs UK, then yes - totally different. In the US, a standard drivers licence (fill out the form on the back on a pack of cheerios to get one) lets you drive a leisure vehicle something up to around 28,000lbs in I think all states, and then above that, some states just let you fill your boots while others you have to apply for a non-commercial CDL (commercial drivers license) - and usually no test or checks, just a payment.