First of all, reach your root-level ‘Library’ and subsequently open your ‘Desktop Pictures’ folder. For this, you just need to click on the image of your hard drive in the Finder. It is usually knows as "Macintosh HD". Click on ‘Library’ afterwards.
Once you have reached the ‘Desktop Pictures’ folder, create a new folder and name it as ‘Desktop Slide Show’.
It is the time to move all your favourite pictures to this new folder. Use ‘Copy’ and ‘Paste’ function to transfer images that you want to use for the slideshow. Dragging photos from one folder to another is not recommended, as you will end up losing all the images from the original folder.
After finishing with the copying, open the ‘System Preferences’. This can be done only by clicking on the Apple logo on the top left side of the screen.
Your Apple computer will come up with plenty of different options. Choose the option that says ‘Desktop and Screen Saver’. It is available in the ‘Personal’ section of the System Preferences. After that, push the ‘Desktop’ button to have all the necessary options about your computer screen.
Click on ‘Choose Folder’ and reach the folder that you earlier created for your slideshow images. After pressing the ‘Choose’ button, check the ‘Change Picture’ box that is on the bottom left side of the "Desktop" Preferences window.
You are also supposed to select the duration, after which the image will change. Click on the drop-down box next to ‘Change Picture’ to have different choices, such as ‘After 05 Seconds’, ‘Everyday’ and ‘When you Log in’.
Don’t forget to check the ‘Random Order’ box, if you want your images to display in random order.
After finishing with all these steps, quit System Preferences simply by pressing Apple Key and Q.