Codes consisting of bars or lines of varying widths and lengths that can be read by a computer using a scanner are commonly known as what?

Introduction / Context:
In supermarkets, libraries, and warehouses, items are often tagged with patterns of vertical bars that represent numeric or alphanumeric data. These patterns are scanned by optical devices at checkout counters or inventory stations, allowing fast and accurate data entry into computer systems. Understanding the name of this familiar technology is an important part of basic computer and commerce awareness.

Given Data / Assumptions:

• The codes consist of bars or lines of different widths and lengths.
• They are computer readable via a scanner.
• The options include ASCII code, magnetic tape, OCR scanner, and bar code.
• We assume the context of retail, logistics, and inventory management.

Concept / Approach:
A bar code is a machine readable representation of data in the form of parallel lines of varying widths and spacing. These lines encode numbers and sometimes letters that identify products or items. A bar code scanner uses a light source and sensor to read the pattern and send the decoded data to a computer. ASCII is a character encoding standard used inside computers, not a visible pattern of bars. Magnetic tape is a storage medium, not a printed code. An OCR scanner is a device that reads printed text, not the name of the code itself. Therefore, the correct term for these line based codes is bar code.

Step-by-Step Solution:
Step 1: Identify where such bar patterns are used in daily life. They appear on product packaging, books, and labels in shops. Step 2: Recall the name of the pattern. These patterns are called bar codes because they use bars to encode information. Step 3: Examine ASCII code. ASCII is an internal coding system for characters, not a visible bar pattern printed on products. Step 4: Examine magnetic tape. Magnetic tape is a storage medium with magnetised data, not printed bars. Step 5: Examine OCR scanner. An OCR scanner is a device used for reading characters on paper, not the name of the code itself. Step 6: Conclude that “A Bar code” is the correct answer.

Verification / Alternative check:
Retail point of sale systems and inventory management materials refer to Universal Product Code (UPC) and European Article Number (EAN) schemes as types of bar codes. The devices that read these patterns are called bar code scanners. Computer literacy texts show images of bar codes as examples of machine readable codes, clearly differentiating them from character encodings like ASCII. Magnetic tape is discussed in storage chapters, and OCR is introduced as optical character recognition for reading printed text, not bar patterns. All of this confirms that the bar and line patterns are called bar codes.

Why Other Options Are Wrong:
Option A (An AsCII code): ASCII is a digital character encoding standard and is not visually represented as bars on products. Option B (A magnetic tape): Magnetic tape is long plastic tape coated with magnetic material used for data storage, not a printed code. Option C (AN OCR scanner): This is the name of a device (scanner) used to read printed characters, not the name of the bar based code.

Common Pitfalls:
Learners sometimes confuse a bar code scanner with the bar code itself and may choose the name of the device instead of the code. Others may see the word “ASCII” and select it because it is a known code, forgetting that ASCII is invisible to the user. To avoid mistakes, remember that the printed pattern of bars on items is the bar code, and the device that reads it is the bar code scanner.

Final Answer:
Codes made of bars or lines that are read by a computer are known as A Bar code.