<operating system> A binary file containing a program in machine language which is ready to be executed (run).
The term might also be, but generally isn't, applied to scripts which are interpreted by a command line interpreter. Executables are distinguished in Unix by having the execute permission bits set, at least for the owner. MS-DOS uses the filename extension ".exe".
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Nearby terms: exec « EXEC 2 « EXEC 8 « executable » executable content » execute » Execute Channel Program