Barcode Card
A barcode is a machine-readable representation of information.  Originally, barcodes stored data in the widths and spacings of printed parallel lines, butoday they also come in patterns of dots, concentric circles, and text codes hidden within images.  Barcodes can be read by optical scanners called barcode readers of scanned from an image by special software.
The barcode code can be mainly classified into linear code (1D) and matrix code (2D).
A linear code is an important type of block code used in error correction and detection schemes.  Linear codes allow for more efficient encoding and decoding algorithms than other codes.
Matrix code is a fictional computer code featured in the Matrix series.  It can store more information within a limited space which includes fingerprint, signature, etc....