what kind of file
what program opens it
compression or audio
what kind of file (expert)
open or closed format
100
mp3
audio file
100
.doc or docx
microsoft word
100
zip
comporession
100
exe
executable pc
100
pdf
closed
200
tar
unix tape archive (contains multiple file sequentially)
200
.html
web browser
200
flac
audio
200
iso
cd image
200
txt
open text file
300
bmp
image bitmap file
300
ppt or pptx
microsoft powerpoint
300
7z
7zip compression
300
jar
java archive (executable class file)
300
wpd
closed word perfect document
400
.ico
icon file in windows
400
.dmg
mac osx (disk image usualy and install program)
400
rar
compression
400
ttf
true type font
400
deb
open debian package manager
500
.xls or .xlsx
microsoft excel file
500
.csv
spread sheet program (excel or sheets or libreoffice)
500
wav
audio (uncompressed lossless)
500
tif
image file
500
mov
closed apple quick time
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