"Sec" can refer to several concepts, but it is commonly used as an abbreviation for "second," a unit of time. One second is defined as the duration of 9,192,631,770 cycles of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. This precise definition helps ensure consistency in timekeeping worldwide. In computing, "sec" can also refer to "security," often used in contexts like cybersecurity or data security. It encompasses measures and practices designed to protect systems, networks, and data from unauthorized access, damage, or theft, ensuring the integrity and confidentiality of information.