Cloud computing offer IT services to the users worldwide on the basis of pay-as-you-go model. Cloud computing refer to network based services which appear to be provided by real server hardware, which in fact are served up by virtual hardware, simulated by software running on one or more real machines. These networked based services and systems are more or less prone to failures. In order to achieve robustness and dependability in cloud computing infrastructure, the failure should be assessed and handled effectively. This paper aims to provide a better understanding of various types of fault tolerance and fault tolerance techniques used in the cloud computing environment.