Should I buy tablet with or without 4G ? What does 4G mean ?

I am considering to buy a tablet. Should I buy one with or without 4G ? What is the meaning of 4G support ?

4G is the fourth generation of broadband cellular network technology. It allows high-speed wireless internet access via SIM card. Tablets with 4G offers possiblity of SIM card insertion and using of the mobile data connection, so you are able to get online anywhere you have network coverage.

If you plan to use high speed mobile data, you should buy a tablet with 4G technology. Tablets with 4G are in general more expensive.