Using Photoshop to edit your images is one of the simplest ways of doing so. However, it is worth considering the way you can make and save your changes. It is possible to edit your images directly to the original file – what is called destructive editing. Once you’ve done that and saved it, there’s no way back to the original image as it’s been saved over. It’s a good option whether you think you won’t need to make any further changes. How can you be sure of that, though? What if you or your clients change their minds? What if you make a mistake?
Since its version 3.0, Photoshop has offered the option of doing non-destructive editing (sometimes called NDE in short). This is the answer for your further changes! This method is possible due to the feature named layers. Instead of saving your edits directly to your original image, non-destructive editing allows you to save it in different layers from the original. Thus, both edited and original images are saved separately. Therefore, you and/or your clients are free to go back to the original image whenever you feel like doing.Experts say that working with non-destructive editing gives you more flexibility besides allowing you to keep the original image resolution intact. This method is not only adjustment layers, though. There are plenty of different ways in Photoshop it can be performed depending on the desired outcome of an image.
You can: duplicate the background layer (this will keep the adjustment layers intact. Letting you start afresh), use smart filters (letting you free to add filters to an image and undo them whenever you change your mind), use layer masks instead of the eraser tool (using a layer mask you can hide off parts of an image rather than using the eraser tool to permanently remove parts it), dodge and burn non-destructively (used to lighten and darken areas of an image), use the clone stamp non-destructively (used to remove bits and pieces you may not want in an image), to name a few.So far you can see many good reasons to use non-destructive adjustments. They can prevent you from start from scratch whenever you change your mind, or even make a mistake. Whether both a destructive and a non-destructive adjustment can lead you to the same results, which makes you wonder “when should I use destructive adjustments?” This kind of adjustment (the destructive one) is very important if you want to keep your work unaltered whenever you work on a shared computer, for instance.
A raster image is created by using pixels in different colors to form it. While a vector image is formed by paths with vectors (mathematical formulas) which are responsible for telling the paths their shapes and colors they are bordered and filled by. The major difference between raster and vector images can be noticed whenever the images are enlarged. Whether a raster image is enlarged, it will lose quality and become blurry. However, when you enlarge (to any size) a vector image, it will keep the same appearance as before due to its mathematical formulas. There are many common raster file extensions (.jpg/.jpeg, .png, .gif, .tiff, .bmp, .exif, .raw, and .webp) and vector file extensions (.ai, .eps, .svg, .vml, and .cgm)….
Source: Working With Images – Site Title