PhotoPlus X3 classifies layers into six different categories. Here's a basic description of each type.
Background Layers – If your image only has a single layer, that layer is generally designated as the background layer when viewing the image in PhotoPlus. Although this is the default layer type for images, background layers have some limitations. As the name suggests, there can only be one background layer for any photo editing project and that layer must be on the "bottom" or beneath all other layers. It's usually more advantageous to convert a background layer to a standard layer before performing any type of edits on the file.
Standard Layers – A background layer is really a special type of standard layer that can't be moved around or have certain effects applied to it. A standard layer is just a "slice" of the image that contains one or more parts of the entire photo. For example, you may have an object that you want to add to an existing photo. The existing photo could act as the background layer and you could add the object to a new layer. The nice thing about standard layers is that they can be moved around, added, or deleted without affecting the rest of the image. Other photo editors often refer to this type of layer as a raster layer, since they contain raster data.
Shape Layers – A shape layer is a type of vector layer that contains lines, shapes, or other type of vector drawings added to an image. For instance, if you want to add an arrow pointing to some object in a photo, that arrow would reside in its own shape layer in PhotoPlus. This makes it easy to change attributes about that shape without affecting the rest of the image.
Text Layers − A text layer is another type of vector layer that is very similar in concept to a shape layer. With this type of layer, you can add text to an image, keeping it separate from other components and easily editable.
Adjustment Layers – An adjustment layer allows you to make corrections to areas such as lighting and saturation without changing the original background layer. This is a particularly nice type of layer to use if you want to experiment with different settings in order to achieve a certain artistic look but also want to be able to get rid of these changes at any time. You can still make adjustments to other types of layers, but then those corrections are tied to whatever layer you use. With an adjustment layer, you can "move" your corrections between other layers so that some elements of the entire final image are affected and others are not.
Filter Layers – A filter layer is similar to an adjustment layer in that it allows you to apply certain filter effects to an image without making changes to the original layer. To use this type of layer, you generally duplicate the layer that you want to apply an effect to, convert it to a filter layer, and then apply the filter. As with adjustment layers, filter layers let you experiment with a whole range of effects that you can delete at any time without losing your original image.