The state of something being in a format that can be edited by the user (ie, text or software).
The addition of the suffix 'ability' to the root word 'edit'. As found on Wictionary: edit + -ability Noun editability (uncountable) The state of being editable. Used frequently in many computer related industries. Example: "Please supply a live native artwork file to maintain editability" "Saving a document as 'Read Only' limits the editability of the file"