What is barcode?

A barcode is a visual representation of data using a pattern of parallel lines (or squares) that a scanner can read. Each line’s width and spacing correspond to numbers or letters, allowing computers to quickly identify products, tickets, or other items.

Let's break it down

  • Lines and spaces: The thick and thin bars, plus the white gaps, form a code.
  • Start/stop symbols: Special patterns at each end tell the scanner where the code begins and ends.
  • Data characters: The pattern in the middle encodes numbers or letters.
  • Scanner: A light source shines on the barcode; the reflected light changes based on the bars, and a sensor translates those changes into digital data.

Why does it matter?

Barcodes turn a long string of numbers into a quick, error‑free visual tag. This speeds up checkout lines, reduces manual entry mistakes, helps track inventory, and enables automated processes in many industries.

Where is it used?

  • Retail stores (product labels)
  • Libraries (book tracking)
  • Shipping and logistics (parcel tracking)
  • Event tickets and boarding passes
  • Manufacturing (part identification)
  • Healthcare (patient wristbands, medication tracking)

Good things about it

  • Fast and inexpensive to produce
  • Highly reliable with low error rates
  • Works with simple, low‑cost scanners
  • Standardized worldwide (e.g., UPC, EAN, Code 128)
  • Enables automation and real‑time data collection

Not-so-good things

  • Limited data capacity (only a few dozen characters)
  • Requires a clear line of sight; damaged or dirty codes may not scan
  • Not ideal for very small items where the barcode would be too tiny
  • Cannot store complex information like images or large text blocks
  • Newer technologies (QR codes, RFID) can offer more features, making barcodes seem outdated in some contexts.