Here, by default both apt-cache and aptitude search for a package on whole list of packages in repository, but output of aptitude shows whether the package is installed on the system or not by giving a per-package flag which here is 'p' indicating that package is present but not installed and 'i' which indicates that the package is installed, whereas apt-cache just lists the package and its one-line detail without telling if package is installed or not.
deviation deÂ·viÂ·aÂ·tion (dÄ'vÄ-Ä'shÉn) n. A turning away or aside from a normal course. An abnormality. Deviant behavior or attitudes. The difference, especially the absolute difference, between one number in a set and the mean of the set.
Frequency deviation () is used in FM radio to describe the maximum instantaneous difference between an FM modulated frequency and the nominal carrier frequency.The term is sometimes mistakenly used as synonymous with frequency drift, which is an unintended offset of an oscillator from its nominal frequency.M applications use peak deviations of 75 kHz (200 kHz spacing), 5 kHz (25 kHz spacing), 2.5 kHz (12.5 kHz spacing), and 2 kHz (8.33 kHz spacing).