OCR stands for Optical Character Recognition or Optical Character Reader. OCR is a technology used to ‘recognise’ or ‘read’ text featured in image files. OCR either converts images of typed, handwritten or printed text from the files – including scanned documents, photos of a document, photos with signs or scenes with type or subtitles on an image – into text that machines can process and search through. Currently, Dropbox uses OCR to recognise the text of your PDFs to make them searchable by their contents.