Owners of newer laptops and computers might not have this problem, but it’s certainly an issue for older machines: If you have a hard drive with a spinning disk (you can usually hear it in action), ditch it. These types of drives simply cannot compete with modern SSDs, which have no physical parts and are faster by an order of magnitude. If your computer takes forever to boot up or you wait way too long for apps to open, it might be your hard drive’s fault.
Some laptops and computers have both an SSD and an HDD, and they are used for different reasons. Usually, the SSD will be small, and tasked with quickly booting up the computer and storing whatever files it can fit. The hard drive is designated for file storage, since hard drive storage is much cheaper. Still, if you find the apps on the HDD are taking too long to load, you can swap that disk out for another SSD.
Apple hasn’t shipped a laptop with a hard drive in years, but did sell iMacs with slow drives up until comparatively recently. It’s entirely possible your machine has one of them, and upgrading to an SSD will increase boot and loading speeds considerably.
Unlike other tech repairs, most machines that have HDDs can be easily upgraded to an SSD. SSDs allowed manufacturers to build computers that are thin, light, and difficult to upgrade. HDDs can be big, and are from an era where computers were more upgradable than they generally are today. Research your particular device to find its guide to swapping out the HDD for an SSD.