XLS is the main extension name used in Excel.
a word processor like: word, open office, note pad, word pad
Access deta base
Pads are used to pad out a mix, harmonically filling empty space, hence the name "pad".
its microsoft word
You're computer is regonising a file as an "Unknown File" only because it has no understanding of that file extention. Right click the file and select "Properties", find the extention name (Eg, .exe) and search for software that will read that extention name. If you're having further problems consult someone on a Technical Help Forum.
The touch pad, or trac pad
I wrote a note on my pad.
it is two words, lily pad
I need an extension cord for my radio, because its cord is not long enough.
exe is the short form of Executable word. exe extract from this word for an extention purpose.
It's often called a "keyhole pad" or a "riser pad."