Contracts are used to form relationships between parties for the sale of goods and services. A mixture of common law and statutory law covers contracts. Contracts for the sale of services are usually covered by common law. Code law usually covers contracts for the sale of goods.

Electronic and online communications have created more efficient ways to enter into contracts. The traditional rules of contract law apply to contracts that are entered into online. Laws such as the Uniform Electronic Transactions Act help make sure that online contracts are enforceable in the same manner as traditional contracts.