I see a lot of confusion on the Cricut MB about .cut, .scut and .svg files and what they are used for. I will see if I can give a brief explanation that will help you understand.
First, Provocraft (PC) created a software for use with your cricuts that is called Design Studio (DS). DS allows you to create new images/objects by using images/objects from those that are on PC's cricut cartridges that you purchase. You do this usually by joining them (welding them together to cut as one new object). You can not "draw" your own objects with DS. You can only use objects from the cartridges. It is also important to note here that you can DESIGN or CREATE objects with ANY cartridge that PC has out and that is loaded in your DS software (note: PC is slow to update the software so it is possible that a cartridge may be out for a little while before it is available for use in the DS software). HOWEVER, you can only CUT the designs you create IF you OWN (or can borrow from a friend) the cartridges used. When you create a file using the DS software and save it, it creates a file name with an extension of .cut. A .cut file can only be used with DS software. It cannot be used with SCAL (Sure Cuts a Lot).
Sure Cuts A Lot (SCAL) software is not a PC product. It was created by Craft Edge to be used with your Cricut machines. You do not have to have DS software to use SCAL. However, you do need to have the most recent "firmware" version on your cricut to use SCAL, and in order to get your firmware updated, you must use the DS software to do that. However, you can download the trial version of DS from PC's Cricut website in order to update your firmware. SCAL was created so that you could use any true type fonts, dingbats and .svg files you might have on your computer to create objects to cut with your Cricut machines. SCAL DOES NOT allow you to use objects from the Cricut cartridges and it CANNOT use the .cut files created by the DS software. When you create a file in the SCAL software and save it, it creates a file name with an extension of .scut. A .scut file can only be used with the SCAL software. It cannot be used with the DS software. However, SCAL can also IMPORT a .svg file (scalable vector graphic).
A .svg file is a file extension for some graphics programs. I am not sure what all graphics programs give you the ability to save as an .svg file. I use Inkscape which is a free program available on the Internet. I believe that Illustrator also allows you to save to a .svg file. With an .svg file, the objects are treated as a 2 dimensional "shape" and thus are more easily resized without any distortion of the image. Text is also treated as an "object" or "shape" when it is in a .svg file. Design Studio (DS) CANNOT import or use in any way a .svg file. However, SCAL (Sure Cuts A Lot) can IMPORT any .svg file that you can find or create! This means that you can "draw" your own images and cut them with your cricut.
If I have a picture or object that I would like to create and cut out with my Cricut, then I simply get it into my computer in some way (draw it, download it from the internet, scan it into my computer) and then IMPORT the image into Inkscape and then with a few simple steps in Inkscape, I can have a .svg file to IMPORT into SCAL and cut with my Cricuts. For example, if you have a stamped image that you would like to create and cut out with your cricut; you can stamp the image, scan it into your computer as a .jpeg, .gif, .tiff or other graphics file, IMPORT that file into Inkscape, do a few steps in Inkscape to create the "parts" and "pieces" you need, and then save it as an .svg file. You then open SCAL and IMPORT that .svg file into it and then "cut" with your Cricut. So now your stamp collection can be used in more ways! The picture posted is an example of a stamped image that I used to make a "die cut" using this method and cut with my Cricut. Sorry, can't share the .scut file for this image. Just posted to show you what the end result looked like!
So to recap:
.cut files - created and used only with Design Studio (DS)
.scut files - created and used only with Sure Cuts A Lot (SCAL)
.svg files - created with a graphics program like Inkscape - can be used with SCAL by importing it; cannot be used with DS. You can scan an image in, draw it on your computer, or download it from the internet. Any file that you can get into your computer you can make into an .svg image with a little work.
Hope this helps someone to better understand these file types and what they can be used with.