CellLabel is an option for Cell which gives the label to use for a particular cell.
CellTags is an option for Cell that gives a list of tags to associate with a cell.
ColorQuantize[image, n] gives an approximation to image that uses only n distinct colors.
CopyFile["file_1", "file_2"] copies file_1 to file_2.
CreateDirectory["dir"] creates a directory with name dir. CreateDirectory[] creates a directory in the default area for temporary directories on your computer system.
DeleteBorderComponents[image] replaces connected components adjacent to the border in a binary image image with background pixels.DeleteBorderComponents[m] replaces ...
DeleteDirectory["dir"] deletes the specified directory.
DeleteFile["file"] deletes a file. DeleteFile[{"file_1", "file_2", ...}] deletes a list of files.
ExpandFileName["name"] textually expands name to have the form of an absolute file name for your operating system.
First
(Built-in Mathematica Symbol) First[expr] gives the first element in expr.