TrueCrypt was an open-source disk encryption software that allowed users to create a virtual encrypted disk within a file or encrypt entire partitions. It provided a way to secure sensitive data by using strong encryption algorithms, making it difficult for unauthorized users to access the information. In 2014, the development of TrueCrypt was abruptly discontinued, and the official website recommended users transition to alternative solutions. Despite its discontinuation, TrueCrypt remains popular among users who appreciate its robust security features and the ability to encrypt data effectively.