MC uses a cache mechanism to speed the display of the Movie & TV show information. Basically MC stores the contents of each nfo file into its own dedicated file so that it only needs to load a single file on start-up instead of a lot of individual files. As information is changed by the user of MC, both the nfo & the cache files are updated.
Fanart are pictures that are based on a Movie or TV Show that have been created by fans of the show.
Used by MC to determine if a particular file is a video file or not. The file extension is the characters after the last '.' character in the filename. As an example, the filename 'video.mpg', the extension is 'mpg'.
A type or category of movie such as Action, Romance, Science Fiction. A particular movie can have more than one genre in order to define its category better.
Used by MC & XBMC to store information relating to a particular video file. Examples of what is stored in the file are the 'Movies Name', 'Genre' & 'Plot'. MC creates the nfo files which are in a compatible format for XBMC to import.
An online movie as far as MC is concerned is defined as a video file that is actually stored on a device that allows direct playback by MC or XBMC.
An offline movie is something like a DVD or Bluray that needs to be physically loaded in order to play the file. MC allows the information about a particular offline movie to still be generated & integrated into MC as if the movie was online.
Posters are pictures depicting a Movie or TV Show. Usually they are designed to advertise an upcoming show. Like fanart, they can be downloaded & shown in MC.
Provides a concise and flexible means for matching strings of text, such as particular characters, words, or patterns of characters. Further information can be found here. http://en.wikipedia.org/wiki/Regular_expression
Sets is a feature of XBMC to allow you to group related movies for display purposes. Instead of listing as an example all of the Star Trek movies, XBMC will list a folder named 'Star Trek Movies' for example. If you select that folder XBMC will then show you all of those movies separately. It is basically a method to reduce the list sizes for large video collections to make it easier to navigate the lists.
A scraper is a list of instructions that a program uses to retrieve information about a Movie or TV Show usually from a web site. A scraper for example may return a movies title, genre or plot. MC uses scrapers to populate all of the information about a Movie or TV Show.
Is a picture of a single frame from a video file. Usually the particular frame is chosen as a representation of what the TV Show episode is about.
TV Shows sometimes have special episodes. These are episodes outside of the normal season episodes. An example of that would be a Christmas special. In most cases they are defined as Season 0 (zero) so that they can be grouped & displayed in a concise way along with the usual seasons.
Are short video clips to advertise an upcoming movie. Some movies have more than one trailer.
An advanced Media Player capable of running on multiple operating systems & hardware. A good summary can be found here. https://en.wikipedia.org/wiki/Kodi_(software)