Create an Animated GIF.

There's a n ANI G.I.F. example at the bottom of this webpage.

First you need to find about 20 images, on a suitable topic from the Internet and when you image search, first use these image options to ensure that you have suitable size images to work with. Eventually all images must be of equal dimensions, to ensure the animation works smoothly and does not 'jump about everywhere'.

Select Images

Tools

Size

Larger than 2mp

Then create a folder for your images.

Open all the images in Photoshop

Check all the sizes, that's both the width and the height. There is no set image size, as you need to check all the images to see what you have and which is the best common size.

This is a long and involved step.

You can always make a large image smaller, but never a small image larger without pixelation (stretch and blur).

If some images are different in size to the others, then the following steps must be taken after you have decided what is going to be your ideal image size.

Set an ideal image size and Image Resize with the 'constrained proportions selector' on.

Re-size all the images to your set size.

However you may get some that are not exactly the size you need.

Then for these images you must use this option, by switching off the constrained proportions.

You can then individually change the sizes, but remember smaller adjustments not larger unless it is less than 10px, which shall not affect the overall image size balance.

Having resized all your images it is time to start the animation process. The end result is a type of Powerpoint slideshow, but this is much better and can be put into a website as an aminated.gif.

In Photoshop, first open the Layers Window. Window/Layers, then in File/Scripts/Load Files into Stack.

This is what shall appear in the Layers Window
Open the Timeline and then select Create Frame Animation.
Should the option Create Video Timeline appear, click on it and a drop down menu appears, then select Create Frame Animation. Then click on the command Create Frame Animation.

Then, using the right side drop down timeline menu box, select Make Frames from Layers.

The Timeline changes with all frames displayed and a dialogue menu. First individually set the frame timing, probably 5 seconds for each frame. Then change the Once to Forever (if that's what you want). If you only want it to play say five times, set the Other option and a new dialogue window appears. Set the number of times you require the animation to play.

Select the Play button on the Timeline bar and play your animation. Make any changes necessary to the frame rates for each animation and any changes to the playback option.
Once all is the way you want, select File/Export/Save for Web, then select Save.
Go to the animation file and double click on it. The file shall open in your browser and then the animation starts up, switching images within your programmed time delay. Click on the image below to see an animation at work.