In personal finances, budgeting is the process of matching income to expenses. The goal of a budgeting process is simply to ensure that more money is "coming in" than "going out". Most budgeted items are fairly inflexible, such as: work wages, rent or mortgage payments, childcare, and utility bills seem to be monotonously similar month after month. The amounts are fairly easy to predict and therefore fairly easy to budget for.
Other items are more difficult. Medical expenses are hopefully irregular, as is the need to replace major appliances or furniture. These types of expenses are more difficult to budget for, but if they are not anticipated they can prove devastating to an established personal budget. Most experts suggest budgeting for them by setting up and relying upon an emergency fund for these unexpected expenses. This can even be done at your bank through automated deductions and deposits. Failure to have a back-up plan will only result in the creation of more debt.