Contract claims in construction are legal disputes that arise between parties to a construction contract. These claims can be based on issues such as delays, defective work, changes in scope, and payment disputes. They can be caused by factors such as ambiguous contract language, poor communication, changes in project scope, and unforeseen conditions. Strategies for resolving contract claims include negotiation, mediation, arbitration, and litigation. It's important to address contract claims in a timely manner to avoid costly and time-consuming litigation.