The mother of all picture format converters

[MGCJerry]

Okay, I know I'm not completely computer literate, but can anyone tell me why I would want to convert file formats? Is this a specialized activity most users would never need/use? If this is a dumb question, I'm sorry--just curious.

I interact with a large number of file formats with all the applications I use. However, for general web-based usage here's what I use.

GIF = simple animatics,transparent icons, images with few numbers of colors, maps
JPG = main image format for graphics
PNG = general usage with more advanced transparency capabilities (alpha channel)

For saving final photos, I go with JPG with no compression. However, if I'm working on an image I stick with a lossless format like BMP or TIFF.

Most normal computer users have no need for a large number of image formats. But once you start getting into graphics (both raster and vector) you will encounter a number of image formats simply for the fact of their overall capabilities.

[Midgardsormr]

In my former capacity as a church technical director, one of my jobs was to coordinate publications for inter-church events that we hosted. I'd receive promotional material from a variety of sources and be tasked with helping to produce event signage and advertising. I would often receive materials in a wide variety of formats and have to convert it to something useable.

Of course, sometimes what I received was just plain useless. A 95px X 100px compressed jpeg portrait of a preacher just isn't very useful for printing posters, no matter what the secretaries think. "Yes, it looks great on their website, but it won't work for the posters. See if they'll send you the original."