What’s the difference between 1D and 2D scanners?

Barcodes (sometimes called barcode symbologies) are visual representations of data encoded in a machine-readable format that is recognized by the International Organization for Standards (ISO) and GS1. Barcode symbologies — generally speaking — come in two forms: 1D (one-dimensional) and 2D (two-dimensional). 1D barcodes were the first type of barcode to be standardized and consist of white and black spaces of varying widths that depend on the specific symbology's standards. 2D barcodes were later introduced as a solution that could store a considerably larger amount of data than one-dimensional barcodes. Two-dimensional symbologies are typically more complex, often incorporating complex geometric patterns that consist of dots, rectangles, hexagons, et al. Like 1D barcodes, the patterns in 2D barcodes depend on the specific symbology's standards. Both 1D and 2D barcodes come in a number of various symbologies, each suited to fit a specific need.

1D Barcodes 2D Barcodes
Represented by black and white "bars" Represented by various geomantic patterns
Typically can only hold a maximum of 25 characters Can contain upwards of 2000 characters
Requires less expensive hardware Requires more expensive hardware
Limited error/damage tolerance Error and damage resistant (damaged barcode can be repaired)
Can only store data horizontally Stores data horizontally and vertically in matrixes
Used for simple data (alphanumeric and some control characters) Used for various types of data including URLs and URIs