Sometimes speed and accuracy is required...
The cheque number and bank account number are printed at the bottom of each bank cheque in special magnetic ink using a special font. These numbers can be detected by an MICR reader.
Special OMR forms are used which have spaces that can be coloured in (usually using a pencil). These marks can then be detected by an OMR scanner.
Common uses of OMR are multiple-choice exam answer sheets and lottery number forms.
OCR is typically used after a page of a book has been scanned. The scanned image of the page is then analysed by the OCR software which looks for recognisable letter shapes and generates a matching text file.
Advanced OCR software can recognise normal handwriting as well as printed text - this is usually called handwriting recognition.
Barcode Reader / Scanner
These lines can be read by a barcode reader/scanner.
The most common use of barcode readers is at Point-of-Sale (POS) in a shop. The code for each item to be purchased needs to be entered into the computer. Reading the barcode is far quicker and more accurate than typing in each code using a keypad.
Barcode can be found on many other items that have numeric codes which have to be read quickly and accurately - for example ID cards.