Export   

Export["file.ext",expr]

exports data to a file, converting it to the format corresponding to the file extension ext.

Export[file,expr,"format"]

exports data in the specified format.

Export[file,exprs,elems]

exports data by treating exprs as elements specified by elems.

Details

Export handles a large number of formats, each typically with many different possible elements. The possible formats are given in the list $ExportFormats, and in the "Listing of All Formats".
Export["file.ext",expr] attempts to render expr in the appropriate format for the file. Among the possible forms for expr is normally the form that would be obtained from Import["file.ext"].
There are four common types of element specifications:

	data representation specifications (e.g. "RawData", "Graphics")
	format specifications (e.g. "GIF", "GZIP", "XLS")
	options, properties, and settings (e.g. ImageSize, SampleRate)
	metadata information (e.g. "Comments")

	"format"	use the default element for the specified format
	elem	export a single element assuming the default format
	{"format",elem}	export an element assuming the specified format
	{"comp₁",…,"format",…}	use also compression formats "comp_i" (e.g. "GZIP")
	{elem₁,{elem₁₁,elem₁₂,…}}	export the expr_i as subelements elem_1i of elem₁

	"Audio"	give sound as an Audio object
	"Data"	give data in a generic form (list, string, etc.)
	"Graphics"	give graphics or geometry as a Graphics object
	"Graphics3D"	give 3D graphics or geometry as a Graphics3D object
	"Grid"	give a grid of data as a list or a Grid, etc.
	"Image"	give images as Image objects
	"Rules"	give explicit rules for elements to export

With the "Rules" element specification, the rules in exprs can have the following basic forms:

	elem->val	a value for a single element
	{elem₁->val₁,elem₂->val₂,…}	values for several elements
	elem₁->val₁,elem₂->val₂,…	an association for several elements
	elem₁->{elem₁₁->val₁₁,…}	values for subelements

Export["!prog",expr,…] exports data to a pipe.
Many options can be given using Export[file,exprs,elems,opts].
The names of options specific to particular formats and elements are normally strings.
Typical general options include Background, CharacterEncoding, ImageSize, ImageResolution, ImageFormattingWidth, SampleRate, etc.
Export[file,NotebookObject[…],…] when possible exports the content of the notebook referenced by the NotebookObject.
Export can be used to export data to cloud and local objects.
Export works with File objects.