Barcode (bar code or line sign)is, presending datas with variety of coding methods for visually enabled machines to read.

Orijinaly, barcode kept datas between paralel lines widths and spaces. But today we can experience it in different types, like point signs, concentric circles, hidden shapes in images.

Barcode can be red by optical readers named Borcode reader or scaned from an image with special softwares. Barcode find use in a wide range  in Automatic Data Identification/ Data Collection applications which increases the data entry accuarcy and speed to computer. While traditionally barcode encoding symbolizes numbers; new symbologies added caps and more to ASCII charecter set. A simple barcodes need to fit more information to the needed area, fort hat reason matrix codes which includes square cells(a kind of Two-dimensional barcode) evolved instead of lines. Nested codes are mixture of two-dimensional codes an done-dimensional codes and it is a process of re-sizing the symbology of traditional one-dimensional for including multiple lines in a frame.