OPSEC" redirects here. OPSEC may also refer to the 501(c)(4) group calling itself Special Operations OPSEC Education Fund.
Operations security (OPSEC) is a process that identifies critical information to determine if friendly actions can be observed by adversary intelligence systems, determines if information obtained by adversaries could be interpreted to be useful to them, and then executes selected measures that eliminate or reduce adversary exploitation of friendly critical information.
Though the above statement is true in its official military format, OPSEC is the process of protecting little pieces of data that could be grouped together to give the bigger picture. OPSEC is the protecting of critical information deemed mission essential from military commanders. Protecting this critical information is through the use of email encryption software, careful of who may be listening to you (like in a hotel bar), paying close attention to a picture you have taken (back ground) or not talking openly on social media sites about information on the unit's critical information list (military deployments, shortages of equipment or movement of VIPs).