1D barcodes scanners (also called linear scanners) are used for scanning 1D barcodes, whereas 2D barcode scanners can also scan 2D barcodes, such as QR codes or Data Matrix.
The main differences between these two types of scanners, are that 2D scanner can read all types of barcodes, but a 1D scanner is restricted only to linear barcodes such as Code 128, EAN13 etc.
2D barcodes are generally more expensive, since they are also capable of reading damaged or poorly printed linear barcodes and can scan from almost any angle (omnidirectional).
What scanner is right for me?
If you only need to scan linear barcodes, and don't use 2D barcodes such as QR Codes, Data Matrix, Aztec or PDF417, then a 1D barcode scanner is most likely what you need.
However, if you plan on using a 2D barcoding system, or require faster scanning to save time, a 2D scanner would be more appropriate.