Zip — fastener, file format, postal code, and other uses

Common meanings

• Zipper (fastener): a mechanical device with two rows of interlocking teeth and a slider used on clothing, luggage and other items.
• ZIP (file format): a popular archive format for bundling and compressing files, commonly identified by the .zip extension.
• ZIP code: the U.S. postal code system abbreviation for Zone Improvement Plan, used to speed mail sorting and delivery.
• Other uses: verbs and slang — to move quickly, to compress data, or informally to mean nothing ("zip, zilch").

The zipper evolved from late 19th and early 20th century fastening experiments; improvements to interlocking teeth and the slider mechanism are often associated with inventors such as Gideon Sundback. The device is valued for quick, repeatable closure and appears in many forms, including metal, molded plastic teeth, and coil types for specialized applications.

The ZIP archive format was popularized in personal computing through the PKZIP utility and later by portable implementations and system support. ZIP files typically use lossless compression methods (one common algorithm is DEFLATE), can contain directories and multiple entries, and often include a central directory record that indexes contents. Many operating systems and file managers provide built-in support for creating and extracting .zip files; additional features such as password protection or stronger encryption may be available in specific tools.

The U.S. ZIP code system was introduced in 1963 to improve mail routing by assigning numeric codes to delivery areas; it is commonly a five-digit number and was later extended with an additional four digits in a ZIP+4 format to identify more specific delivery segments. Other countries use postal-code systems with different names and formats.

In informal speech, zip can mean energetic motion or nothing at all depending on context. In computing, to zip ordinarily means to compress files into a ZIP archive, and the lowercase form or the file extension helps disambiguate this use. When encountering the word, consider capitalization, surrounding terms, and subject matter to determine whether it refers to a fastener, an archive, a postal code, or casual usage.