At their most basic definitions, a custard uses eggs and a pudding uses cornstarch. For example, crème brulee is a custard while your classic chocolate pudding is simply that – pudding. However, there can be overlap in baking, depending on how you want your custard or pudding to be. A pudding can be made more firm with the use of eggs such as the cream pudding that goes into cream pies such as Boston cream pie. Experiment in the kitchen a bit with pudding and eggs and find out which you like better.