What Is a Contract and Types of Contracts

Everyone · Explainer · Updated October 1, 2026 · LearnLife Editorial

What is a contract in plain words?

A contract is a promise or set of promises that the law will enforce. It involves two or more people or businesses agreeing to do—or not do—something in exchange for something else, such as money, services, or goods. Think of a contract as a formal handshake backed by the law. Without a contract, there might be no way to hold someone accountable if they don’t keep their word.

For a contract to be valid, it generally needs four things: an offer, acceptance, consideration, and mutual intent to create legal obligations. For example, if you agree to buy a used laptop from a friend for $500, your friend offers to sell, you accept, you promise to pay money (consideration), and you both intend to enter a legal deal. That is a simple contract.

Contracts are everywhere, from signing up for a phone plan to renting an apartment. Knowing what a contract is helps you understand the agreements you enter daily and when those agreements can be enforced.

How do different types of contracts work?

Contracts are categorized based on how they are formed and what they require. Knowing these types helps you recognize what kind of agreement you have and what rules apply.

• Written contracts: These contracts are recorded on paper or electronically and signed by the parties. For example, a lease agreement or a job offer letter.
• Oral contracts: Agreements made by spoken words without written proof. For example, agreeing with a neighbor to mow their lawn for $50.
• Express contracts: Terms are clearly stated, either orally or in writing, such as when you sign a contract to buy a car.
• Implied contracts: These arise from actions or facts. For example, when you enter a restaurant and order food, you imply you will pay.
• Bilateral contracts: Both parties make promises to each other. Most contracts are bilateral, like a sales contract where one promises to deliver goods and the other promises to pay.
• Unilateral contracts: One party makes a promise that the other party can accept only by performing a specific act, like a reward for finding a lost dog.
• Executed contracts: Both parties have fully performed their obligations, such as after you pay for and receive a product.
• Executory contracts: Some obligations are still outstanding, like when you sign a contract to buy a car but will pay in installments.

Hypothetical example

Imagine you hire a painter to repaint your living room for $1,200. You both sign a written agreement outlining the price, timeline, and work scope. This is a written, express, bilateral contract because both parties promise something. While the painting is underway, the contract is executory. After the painter finishes and you pay, it becomes executed.

Why do contract types matter for you?

Understanding contract types helps you protect yourself and avoid problems. For example:

• Oral contracts can be legally binding, but since there is no written proof, it’s harder to enforce them if disagreements arise.
• Written contracts clearly show each party’s promises, making disputes easier to resolve.
• Recognizing unilateral contracts helps you identify offers made for specific actions, preventing misunderstandings.
• Knowing the difference between executory and executed contracts helps you track whether obligations have been met.

For instance, if you rent an apartment, the lease is a written bilateral executory contract because both tenant and landlord have promises to fulfill over time. If you don’t pay rent or the landlord doesn’t maintain the property, either party may be breaching the contract.

By knowing the type of contract, you can better understand your responsibilities and what to do if problems occur.

What are common terms people confuse with contracts?

People often mix up contracts with other related terms that sound similar but are different:

• Agreements: All contracts are agreements, but not all agreements are contracts. An agreement is a mutual understanding without necessarily being legally binding.
• Promises: A casual promise might not be enforceable. A contract involves promises backed by legal obligations.
• Offers: An offer is a proposal to enter a contract but is not binding until accepted.
• Leases and licenses: These are specific types of contracts granting rights. A lease gives the right to use property, while a license permits certain uses but does not transfer ownership.
• Terms and conditions: These are parts of a contract detailing the rights and duties of the parties.

For example, a handshake deal may be an agreement but might not meet contract requirements if key elements like consideration are missing. Understanding these differences helps clarify when you have a legal contract.

What steps should you take before signing a contract?

Before agreeing to a contract, follow these steps to protect yourself:

1. Read the entire contract carefully. Don’t rush. Make sure you understand all terms, including payment, deadlines, and responsibilities.
2. Ask questions about anything unclear. Use exact questions like, “What happens if I can’t pay on time?” or “Are there penalties for early termination?”
3. Request the contract in writing whenever possible. Written contracts provide proof and clearer terms than oral agreements.
4. Look for key elements: Check that the contract clearly states the offer, acceptance, consideration, and parties’ names.
5. Consider consulting a trusted adult or professional if the contract is complex or involves significant money.
6. Keep a signed copy for your records. If the contract is electronic, save a PDF or print it.
7. Check state laws if unsure. Some contracts require specific language or forms depending on where you live.

For example, if you are offered a contract for freelance work, read it fully. Verify payment terms, deadlines, and rights to your work. Write down questions and get answers before signing.

How can you recognize when a contract may not be enforceable?

Not all contracts are legally binding. Some factors can make a contract invalid or unenforceable:

• Illegal purpose: Contracts involving illegal acts, like selling stolen goods, are not enforceable.
• Lack of capacity: Minors or people not mentally able to understand the agreement usually cannot be legally bound.
• Duress or fraud: If one party was forced or tricked into the contract, it may be voidable.
• No consideration: A contract must involve an exchange of value; a mere promise without consideration is generally not enforceable.
• Statute of Frauds: Certain contracts, like those involving real estate or agreements lasting over a year, must be in writing to be enforceable under state laws.
• Unclear terms: If the contract’s terms are too vague, a court may not enforce it.

For example, if you sign a contract under pressure or without understanding, you may be able to cancel it. If the contract requires something illegal, it has no legal effect.

What should you do if a contract dispute arises?

If you believe someone has broken a contract, here are steps to take:

1. Review the contract carefully. Understand your rights and obligations.
2. Try to resolve the issue directly. Communicate clearly and calmly with the other party to find a solution.
3. Document everything. Keep emails, texts, receipts, and notes of conversations.
4. Consider mediation or arbitration. These are alternative ways to resolve disputes without court.
5. Seek legal advice or assistance. Contact a local legal aid organization or consult a lawyer, especially if the dispute involves significant money or rights.
6. Know your deadlines. Contract claims often have time limits, called statutes of limitations, which vary by state.

For example, if a contractor doesn’t complete work as agreed, first talk to them about your concerns. If unresolved, check the contract for dispute resolution steps or seek legal help.

Frequently asked questions

Can a contract be made just by text messages or emails?

Yes, contracts can be formed through electronic communications like texts or emails if they show a clear offer, acceptance, and consideration. Keep copies of these messages as proof, since they may be harder to enforce than formal written contracts.

What is the difference between a contract and a handshake agreement?

A handshake agreement is an informal oral agreement without documentation. It can be a valid contract if it contains essential elements, but it’s harder to prove in disputes compared to a written contract.

Can a minor enter into a contract?

Generally, minors (under 18) cannot be legally bound by contracts except for necessities like food or shelter. Contracts signed by minors are often voidable, meaning they can cancel the agreement.

What does “consideration” mean in a contract?

Consideration refers to something of value exchanged between parties, such as money, services, or goods. It is a necessary part of a contract that shows each party is giving or promising something.

How do I know if a contract is legally enforceable in my state?

Contract laws vary by state. To confirm enforceability, check your state’s laws or seek advice from legal aid or a lawyer, especially for important or complex contracts.