If you have a logo, you need to have it in vector format, so you can always supply it to creative professionals who do work for you. if you know what that means, read no further. if not, no worries, it's a simple thing, read on:
vector artwork comes in a number of file formats, but '.eps' ('encapsulated postscript' to be exact) and .svg (scalable vector graphics) are the most common. in fact, svg's name says it all: scalable. this means that designers can apply your logomark at any size and it will look great. if your logo designer was worth their salt, they created your mark in a program like Adobe Illustrator, meaning it was made using vector technology. so they should already have it in this format. also, they should have supplied it to you as an .eps or .svg already.
too often though, the vector file gets lost, especially when it's been years and years since the logo was produced and noone left in the organization even knows who made it (or how to get ahold of them!). all anyone can find are what's called raster files, like .jpg, .gif or .png. these files are less useful to the designer because they are based on pixels: tiny squares in a grid that make up the image. perhaps you've seen them as visible squares around the edges of graphics (see my example). those were blown up and have lost their crisp quality because they are only intended to be displayed at a specific size.
i've come across this issue more times than i can count, where my new client can't readily provide a vector version of their logo. often, it has to be recreated because it actually takes me less time to do that than locate the original designer!
if you have any questions about this topic, or need some help getting your logo into this format, feel free to contact me.