What is the difference between an SVN checkout and an SVN export?

They are the same except that Export doesn't include the.svn folders and Checkout does include them. Also note that an export cannot be updated.

When you do a Subversion checkout, every folder and subfolder contains an.svn folder. These.svn folders contain clean copies of all files checked out and.tmp directories that contain temporary files created during checkouts, commits, update and other operations.

An Export will be about half the size of a Checkout due to the absence of the.svn folders that duplicate all content.

NOTE: An export cannot be updated like a checkout.