Just-in-time blocking is like a bouncer at a party. You know how bouncers only let people into the party when they're on the guest list? Well, just-in-time blocking is similar. It only allows you to see certain information or access certain websites or apps when it's needed for your work, and you're authorized to use them.
Let's say you're at a party, but you're not feeling well, and you need some medicine. If you're trying to buy medicine online, just-in-time blocking will check to see if you're authorized to do so, and if it's part of your work or not. If it's not part of your work, you won't be able to access the website. This way, you won't waste any time looking for something you don't need.
Just-in-time blocking is often used by companies to make sure their employees aren't wasting time on the job. It's like a gatekeeper that only opens the gate when the right keys are presented. So, when you're at work, just-in-time blocking will only let you access what you need to get your work done.