There is often confusion between Saving a Project and Exporting/Sharing a Video from that Project.
Let’s look at what a Project file is. In PrE, this is a .PREL file. In PrPro, it’s a .PRPROJ file. These are just XML database files, that define the Project, show where the media used in that Project was located the last time that you had the NLE (Non Linear Editor) program and that Project, open. Then, there are instructions as to what one has done to those media Assets. There is no media, of any sort included in it.
If you open it up in WordPad, or an XML editor, it looks something like this:
<?xml version="1.0" encoding="UTF-8"?>
<Project ObjectID="1" ClassID="62ad66dd-0dcd-42da-a660-6d8fbde94876" Version="20">
Note: in the actual Project file, there will be much indentation, that does not show up above.
There is much, much more, but this should give you an idea. You cannot "play" this file with any media player. Remember, there is zero media in it, only links to that media. Also, there are only two programs that can do anything but allow one to edit the various text lines in a Project file. PrPro can open both types, .PREL’s and.PRPROJ’s, with a few exceptions. PrE can ONLY open .PREL files and will give you an error that "this Project was created in PrPro. Use that program to open this Project." There are no exceptions to this, though who knows if PrE 8 will be able to open .PRPROJ files?
Now that we know there is no media in these files, what good are they? Well, they contain links to the location of the media and also instructions on what one has done to that media. They are the instructions for PrE and PrPro, with descriptions of all edits. They are the working tools of both of these NLE programs. They also must be set up, before one can do anything else in these programs.
As one works with the Project, they will want to Save their Project files, or any edits will be lost. There are basically three ways to this, plus one additional variation.
First, there is Save. It records all operations and instructions to the previously created Project file, overwriting the previous version. I do this often and usually use Ctrl+s for this purpose.
Next, we have Save_As. This does a Save, but with two variations: it allows one to set a new name, or location for this Project file. I use this and increment the Project file’s name, as I go. This does NOT overwrite the existing Project file, but writes another one, with the name, or location that the user assigns. The second part of this, and quite important, is that not only does it Save with the new name/location, but it keeps this new Project open in the NLE. You are now working on the new version, and not the original. To me, this is especially useful, if I want to leave the original version untouched, in case I need to go back to it at some date. After a day of editing, or after some big changes, I’ll make sure to do this, so I have the original, plus this newly edited version. By incrementing by 1, I know that if I am working with [Project Name]_05, it came after [Project Name]_04, so it is newer.
Then, we have Save_As_a_Copy. How does this differ from Save_As? The biggest difference is that it does not overwrite the original, allows one to change, or increment, the file name/location, but it does NOT stay open in the program. You are still working with the original version, and this Save_As_a_Copy version is tucked away, in case you need it at some time. I use this, when I just want a record and a backup of that moment for possible later use. It’s more of a "snapshot" of how things were at that moment.
Last is the "variation" that I mentioned. This is AutoSave. Depending on one’s Preferences, these will be stored in the AutoSave folder in the Project’s hierarchy. By default, one will have five of these and they will reflect that they are AutoSave files. Note: one must do a first Save in an editing session to start AutoSave, which will make an AutoSave copy at the time interval set in Preferences. Also, Premiere is pretty smart. It will NOT just AutoSave every 5 mins (or whatever time interval is set in Preferences), unless some work has been done. This is a good thing, as AutoSave will overwrite the previous files in that folder. If you go to lunch, if it did not keep track of edits being done, one would end up with 5 exactly identical copies of the same file in AutoSave. This would not be that useful.*
Now, because it does overwrite your previous AutoSave files, you need to pay close attention, should you ever need to use an AutoSave Project file. By default, there will be five files, _001, _002, _003, _004 and _005. However, because of that overwriting (basically FIFO), you need to change the View in Windows Explorer to Details, and sort by Date/Time, to make sure that you are getting the latest version. Remember, _003 could well be newer than _005. Watch out for this, and do the Sort on Date/Time to be sure.
Hope that this helps one distinguish between Project files and Video FROM that Project, plus give some tips on Save, Save_As, Save_As_a_Copy and also AutoSave.
* It has come to my attention that as of PrPro CS3, things have changed with Auto-Save. One does not need to do an initial Save to start Auto-Save, but if left Open, though no editing is being done, the Auto-Save will keep on overwriting the files at the set interval, say every 5 mins.. What this means is that if you leave a Project Open for 25 mins., have the number of Auto-Saves at the default of 5 and the default of every 5 mins., you will have 5 copies of the same Project file. I do not know what Adobe was thinking here, as Auto-Save should not be active, if no editing is being done. I often have a Project Open, but am working in PS, AI, or Encore, so there is no editing being done in PrPro, but there soon will be. I do not want all previous Auto-Saves being overwritten with the same exact file. With PrPro CS3 or higher, I strongly recommend that one does a lot more Save_As and Save_As_a_Copy, than in previous editions, or they might be in for a rude surprise, if they went to lunch, or just left the Project Open for a half-hour.