Resource: employees
Layer Comps - Beginner - Old fashion way
If you have only a few images to convert to Layer Comps, you don't have to use the Layer Comp panel or Variables. You can do it the old fashion way.
Layer Comps - Intermediate - Using Layer Comp Dialog Box
Layer comps allow you to create, manage and preview a variety of images from the same Photoshop file by experimenting with different layer comps (short for compositions). This can save you a ton of time if you need to create a multitude of images that are basically the same but need different text and graphics on each image. A file with a layer comp is smaller than if you had to create each comp separately in a different file. You also have the added advantage of having all of the layer comps in one file for convenience as well as the ability to use them with other applications like Illustrator and InDesign.
Layer Comps - Advanced - Using Internal Variables
Using variables in Photoshop is akin to using layer comps. The major different is that when you use variables you are retrieving the data from a data source instead of just turning layers on and off. Photoshop can use layer names as variable placeholders. Then, these placeholders can be "filled" with data from a data source which could be an internal data source. This is akin to using a mail merge program or even server-side scripting like Coldfusion, ASP(.NET), PHP or JSP. Like Layer comps, this can save you a ton of time if you need to create a multitude of images that have basically the same layout (template) but need different text and graphic on each image (i.e., business cards, trading cards, web ads, web banners, posters, etc.).
NOTE: Using variables in Photoshop with an internal data source is similar to using variables with an external data source with the exception that the data is created INSIDE of Photoshop and is done later in the process. It is best used if you have only a few images that you want to use.
Layer Comps - Expert - Using External Variables
Using an external data source is similar to the internal data source and is best used when you have a lot of images you ant to convert to Layer Comps.