People use credit for many personal reasons, but the compelling motive typically relates to the desire to purchase something today and pay for it in the future. With a loan, someone can make a large purchase and spread the costs out by making installment payments over time.
In some cases, people make emergency purchases on credit, such as car repairs or medical services. Time may not allow the person to save up the funds. Some people use credit as a convenient way to pay for things, but they pay their balances off quickly. Building a credit history and getting rewards are other motives for using credit.