Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: I feel stupid asking this question but what is green screen program and do I need it to use this digital backgrounds collection?
Document: I was looking for some digital backgrounds for both some photography and to use in some green screen videos. This collection is exactly what it says it is. I've dropped them behind some stills and placed them on the video line in Pinnacle Studio. In studio you need to zoom to fill the frame so some tall narrow images either get cut or zoomed in tight but several of the ones I chose turned out fine. Some effectiveness will depend on your editing software.
This product is great! They shipped my order the same day and received it 2 days later! Their shipping is impecable! You get 100 backgrounds to choose from and all of them are beautiful. The best part of it is...... you don't have to have a green screen to use it! All you need is a photoshop program on your computer! Love the product.
I have to admit I am a bit of a digital background collector. I saw this while looking for some muslin backdrops and thought I would order it. The price was right and I found the quality to be pretty good. Because I have a lot of backgrounds in my collection I found a few duplicates but not many. I do a lot of green screen so these will come in handy. The disk got to me quickly and in good shape. The price was great.
This collection of digital backgrounds are great for a photo novice like me. Work well with Photoshop Elements 7 and is easy to use. I love to photograph my grandbabies and this adds much to my collection of backdrops to choose from. Use a green or white sheet background, take your photo and then clip and paste it into the backgrounds on this CD. Works well and looks real!
I purchased Top 100 Premiere Digital Backgrounds Collection from Amazon.Com. I am enjoying being creative using the digital backgrounds collections. If you have an editing software program and a little imagination, you can get thousands of variations by using less than a forth of the backgrounds in this collection. I have the Smart Photo Editor program and several others and this one program has endless possibilities.
I have tried working with this program and Corel  and have had no luck. I'm not sure if I need a different editing program or what the case is. It said that it could be used with Corel. Maybe I am missing something.... Oh well
I am a total beginner with green screen techniques and didn't want to spend a lot to experiment so purchased this primarily because of the price. I was very happily surprised. The backgrounds offered cover a nice range of themes but what I valued most about this purchase was the very helpful online tutorials which really walked me step-by-step through the process of doubling up images.
no instructions on how to use this cd.so I am very unhappy with this.I feel I wasted my money on this
I wouldn't recommend this product to my worst enemy, total waste of time! If you want to use digital backgrounds use your own photos, the quality will be 100x better!
The name itself is EZbackgrounds. It is NOT easy to do. It didn't tell me that I need special photography software to use it. The CD is just pictures; it's not even software. Not happy at all.
Answer: I don't think you have to use green screen but it makes it easier.  Green screen is taking your photos with a green backdrop so the editing process is easier.  If you have Photoshop you can do the editing without the green backdrop.