Computer Lessons – Filename Extensions

Computer Lessons - Filename Extensions

 

  • One popular method used by many operating systems is to determine the format of a file based on the end of its name—the letters following the final period. This portion of the filename is known as the filename extension.
  • e.g. Filename.ext
  • For example, HTML documents are identified by names that end with .html (or .htm)
  • e.g. index.html or index.htm
  • The extensions have usually three-characters.,

we will talk about some of the common filename extensions.

.exe, .bat (batch file)

.dat — data file, usually binary data proprietary to the program that created it

.rar, .zip, .jar, .tar, .arj: Compressed file

.html

.txt

.txt: Text file

.rft: Rich Text document

.doc: Microsoft Word

.docx: Microsoft Word

.pdf: Portable Document Format (PDF)

.pages: Apple Pages

.xls: Microsoft Excel

.xlsx: Microsoft Excel

.numbers: Apple Numbers

Video formats

  • .3gp — the most common video format for cell phones
  • .mov (QuickTime) — container which enables any form of compression to be used
  • .avi — container (a shell, which enables any form of compression to be used)
  • .flv — Flash video (encoded to run in a flash animation)
  • .mkv— Matroska is a container format,
  • .mpeg, .mpg, .mpe, .mp4 (MPEG): multimedia container
  • .wmv — Windows Media Video
  • .swf — Macromedia Flash

Audio formats

  • .mp3
  • Wave Sound (.wav)
  • Adaptive Multi-Rate (.amr)
  • Windows Media Audio (.wma)
  • Advanced Audio Coding (.aac)
  • MIDI (.mid)

Pıcture formats

  • jpg, .jpeg Joint Photographic Experts Group
  • .png: Portable Network Graphic (lossless)
  • .ico: a file format used for icons
  • .bmp: Microsoft Windows Bitmap formatted image
  • .gif: Graphics Interchange Format
  • .tif: Tagged Image File Format (usually lossless)
  • .gra: TARGA image

File Extentions for BiologIST

  • Molecular biology and bioinformatics:
  • .ab1 — In DNA sequencing, chromatogram files used by instruments from Applied Biosystems
  • .ace — A sequence assembly format
  • .caf — Common Assembly Format for sequence assembly
  • .embl — The flatfile format used by the EMBL to represent database records for nucleotide and peptide sequences from EMBL databases
  • .fasta — The FASTA file format, for sequence data. Sometimes also given as FNA or FAA (Fasta Nucleic Acid or Fasta Amino Acid).
  • .fastq — The FASTQ file format, for sequence data with quality. Sometimes also given as QUAL.
  • .gb, .GenBank — The flatfile format used by the NCBI to represent database records for nucleotide and peptide sequences from the GenBank and RefSeq databases