• Hyperfine structure
  Hyperfine structure
  The term hyperfine structure refers to a collection of different effects leading to small shifts and splittings in the energy levels of atoms, molecules and ions. The name is a reference to the fine structure which results from the interaction between the magnetic moments associated with electron...
  
  
• Hereditarily finite set
  Hereditarily finite set
  In mathematics and set theory, hereditarily finite sets are defined recursively as finite sets consisting of 0 or more hereditarily finite sets.-Formal definition:...
  
  
• Hexafluorosilicic acid
• WHFS (historic), 'HFS was a slang abbreviation for the radio stations with that call sign in the Washington / Baltimore area
• Hemifacial spasm
  Hemifacial spasm
  Hemifacial spasm or HFS is a neurological disorder in which blood vessels constrict the seventh cranial nerve and cause varying degrees of facial spasm, typically originating around the eye of the afflicted side of the face...
  
  , a neurologic disorder which causes involuntary spasms in one side of the face
• Hospitality Franchise Systems, (HFS) later Cendant
• Haddonfield Friends School
  Haddonfield Friends School
  Haddonfield Friends School is a private, Quaker coeducational day school which has educated students for 225 years. It is located in Haddonfield, in Camden County, New Jersey, United States...
  
  , a Quaker school in Haddonfield, NJ
• Hatfield and Stainforth railway station
  Hatfield and Stainforth railway station
  Hatfield and Stainforth railway station serves the Doncaster suburbs of Hatfield and Stainforth in South Yorkshire, England.The original station, known until the 1990s as "Stainforth and Hatfield" and was built in 1866 as a replacement for the South Yorkshire Railway's Stainforth when their line...
  
  , England; National Rail station code HFS

In computing

• Hardware Functionality Scan
  Hardware Functionality Scan
  A Hardware Functionality Scan is conducted in order to verify that a certain device is really what it claims to be. It's patented by Microsoft....
  
  
• Hi Performance FileSystem
  Hi Performance FileSystem
  Hi Performance FileSystem, not to be confused with OS/2's HPFS or Apple's Hierarchical File System, is a file system used in the HP-UX operating system. It is a variant of the Unix File System....
  
  , a file system used by the HP-UX operating system
• Hierarchical File System
  Hierarchical File System
  Hierarchical File System is a file system developed by Apple Inc. for use in computer systems running Mac OS. Originally designed for use on floppy and hard disks, it can also be found on read-only media such as CD-ROMs...
  
  , a file system used by Apple Macintosh computers
• HTTP File Server
  HTTP File Server
  HTTP File Server, otherwise known as HFS, is a free web server specifically designed for publishing and sharing files.The complete feature set differs from other web servers; it lacks some common features, like CGI, but includes, for example, counting file downloads. It is even advised against...