The statement accurately describes the fundamental nature of a quasi-contract. Unlike traditional contracts, which are formed by the express or implied agreement of parties, quasi-contracts are obligations imposed by law, based on principles of justice, equity, and good conscience, to prevent unjust enrichment. They are not true contracts because they lack the essential elements of a valid contract, such as offer, acceptance, consideration, and mutual assent.

Nature and Basis of Quasi-Contracts:

1. Imposed by Law (Judicial Principles): Quasi-contracts are not created by the will or intention of the parties but are rather obligations that the law imposes on one party to prevent them from unfairly benefiting at the expense of another. The court constructs a fictional contract where none exists in reality.
2. Prevention of Unjust Enrichment: The primary objective behind the concept of quasi-contracts is to prevent 'unjust enrichment.' Unjust enrichment occurs when one person retains money or benefits that in justice and equity belong to another. The law intervenes to restore the benefit to the rightful owner.
3. No Agreement: There is no offer, acceptance, or consensus ad idem (meeting of minds) between the parties. The obligation arises irrespective of the parties' intentions to enter into a contractual relationship.
4. Resemblance to Contract: While not actual contracts, they are termed 'quasi-contracts' because the remedies available for their breach are similar to those for breach of contract (e.g., recovery of money or compensation).

Types of Quasi-Contracts (as per Indian Contract Act, 1872, Chapter V, Sections 68-72):

1. Supply of Necessaries to Persons Incapable of Contracting (Section 68): If a person incapable of entering into a contract (e.g., a minor or a person of unsound mind) or anyone whom he is legally bound to support, is supplied by another person with necessaries suited to his condition in life, the person who has furnished such supplies is entitled to be reimbursed from the property of such incapable person. This is not a contract because the incapable person cannot contract, but the law imposes an obligation to pay for necessaries.
2. Payment by an Interested Person (Section 69): A person who is interested in the payment of money which another is bound by law to pay, and who therefore pays it, is entitled to be reimbursed by the other. For example, if a tenant pays the landlord's property tax to prevent his own property from being seized, the landlord is bound to reimburse the tenant.
3. Obligation of Person Enjoying Benefit of Non-Gratuitous Act (Section 70): When a person lawfully does anything for another person, or delivers anything to him, not intending to do so gratuitously, and such other person enjoys the benefit thereof, the latter is bound to make compensation to the former in respect of, or to restore, the thing so done or delivered. For instance, if a tradesman leaves goods at a wrong house by mistake, and the owner of that house consumes them, he is bound to pay for them.
4. Responsibility of Finder of Goods (Section 71): A person who finds goods belonging to another, and takes them into his custody, is subject to the same responsibility as a bailee. He must take reasonable care of the goods and make reasonable efforts to find the true owner. If he sells them, he must account for the proceeds.
5. Money Paid by Mistake or Under Coercion (Section 72): A person to whom money has been paid, or anything delivered, by mistake or under coercion, must repay or return it. For example, if a bank mistakenly credits an amount to a customer's account, the customer is bound to return it.

Conclusion:

In essence, quasi-contracts are legal fictions created by courts to ensure fairness and prevent one party from unjustly enriching themselves at the expense of another. They are rooted in the principles of natural justice and equity, rather than the mutual consent and agreement that form the bedrock of traditional contracts. They represent a legal obligation imposed by the judiciary to achieve a just outcome where a formal contract is absent.