A Data Matrix code is a two-dimensional matrix barcode consisting of black and white square modules arranged in either a square or rectangular pattern. The information to be encoded can be text or raw data.

Usual data size is from a few bytes up to 2 kilobytes. The length of the encoded data depends on the symbol dimension used.

Error correction codes are added to increase symbol strength: even if they are partially damaged, they can still be read. A Data Matrix symbol can store up to 2,335 alphanumeric characters.

Data Matrix symbols are square and made of cells, that is little squares that represent bits. Depending on the situation a white module is a 0 and a black module is a 1, or vice versa.

Every Data Matrix is composed of at least two finder patterns or handles and two syncs. Handles are two perpendicular lines, coloured the same way as 1 modules, while syncs are like handles with the difference that they are made of alternating black and white modules. Handles achieve a good alignment with the symbol, while syncs sample modules correctly.

If the matrix dimension grows, more syncs and handles are added up to 8 both horizontally and vertically. Symbol sizes vary from 8×8 to 144×144.

Data Matrix codes are becoming common on printed media such as labels and letters. The code can be read quickly by a scanner which allows the media to be tracked, for example when a parcel has been dispatched to the recipient.

For industrial engineering purposes, Data Matrix codes can be marked directly onto components, ensuring that only the intended component is identified with the Data Matrix encoded data. The codes can be marked onto components with various methods, but within the aerospace industry these are commonly industrial ink-jet, dot-pen marking, laser marking, and electrolytic chemical etching (ECE). These methods give a permanent mark which should last the lifetime of the component.

After creation of the Data Matrix code, the code is usually verified using specialist camera equipment and software. This verification ensures the code conforms to the relevant standards, and ensures it will be readable for the lifetime of the component. After the component enters service, the Data Matrix code can then be read by a reader camera, which decodes the Data Matrix data which can then be used for a number of purposes, such as movement tracking or inventory stock checks.