COPY

Copy one or more files to another location

Syntax
      COPY source destination [options]

      COPY source1 + source2.. destination [options]

Key
     source :  Pathname for the file or files to be copied.

        /A  :  ASCII text file (default)
        /B  :  Binary file copy - will copy extended characters.

destination :  Pathname for the new file(s).

        /V  :  Verify that the new files were written correctly.

        /N  :  If at all possible, use only a short filename (8.3) when creating
               a destination file. This may be necessary when copying between disks
               that are formatted differently e.g NTFS and VFAT, or when archiving 
               data to an ISO9660 CDROM.

        /Z  :  Copy files in restartable mode. If the copy is interrupted 
               part way through, it will restart if possible. (use on slow networks)

        /Y  :  Suppress confirmation prompt (Windows 2000 only)

        /-Y :  Enable confirmation prompt (Windows 2000 only)

Prompt to overwrite destination file

NT 4 will overwrite destination files without any prompt, Windows 2000 and above will prompt unless the COPY command is being executed from within a batch script.
To force the overwriting of destination files under both NT4 and Windows2000 use the COPYCMD environment variable:

SET COPYCMD=/Y

This will turn off the prompt in Win2000 and will be ignored by NT4 (which overwrites by default)

Binary copies
"COPY /B ... " will copy all the files in binary mode , you can also put /B after any one file to copy just that file in binary.

Combine files
To combine files, specify a single file for the destination, but multiple files as the source. To specify more than one file use wildcards or list the files with a + in between each (file1+file2+file3)
When copying multiple files in this way the first file must exist or else the copy will fail, a workaround for this is COPY null + file1 + file2 dest1

COPY will accept UNC pathnames

Copy from the console (accept user input)

COPY CON filename.txt
Then type the input text followed by ^Z (Control key & Z)

To do this in Powershell use the following function:

function copycon {
[system.console]::in.readtoend()
}

Examples:

In the current folder
COPY oldfile.doc newfile.doc

Copy from a different folder/directory:
COPY "C:\my work\some file.doc" "D:\New docs\newfile.doc"

Specify the source only, with a wildcard will copy all the files into the current directory:
COPY "C:\my work\*.doc"

Specify the source with a wildcard and the destination as a single file, this is generally only useful with plain text files.
COPY "C:\my work\*.txt" "D:\New docs\combined.txt"

Quiet copy (no feedback on screen)
COPY oldfile.doc newfile.doc >nul

"Success seems to be connected with action. Successful men keep moving. They make mistakes, but they don't quit" - Conrad Hilton

Related:

ROBOCOPY - Robust File and Folder Copy
XCOPY - Copy files and folders
MOVE - Move a file from one folder to another
Fcopy - File Copy for MMQ (copy changed files & compress. (Win 2K ResKit)
Permcopy - Copy share & file ACLs from one share to another. (Win 2K ResKit)
PowerShell: Copy-Item - Copy an item from one location to another
Equivalent bash command (Linux): cp - Copy one or more files to another location.