You go with your crush 😍 to get fast food 🍔, you stand in line while the cashier 💁 takes the orders from the people in front of you.
Then it’s your turn, you place your order of 2 very fancy burgers 🍔 for your crush 😍 and you.
You pay 💸.
The cashier 💁 says something to the cook in the kitchen 👨🍳 so they know they have to prepare your burgers 🍔 (even though they are currently preparing the ones for the previous clients).
The cashier 💁 gives you the number of your turn.
While you are waiting, you go with your crush 😍 and pick a table, you sit and talk with your crush 😍 for a long time (as your burgers are very fancy and take some time to prepare ✨🍔✨).
As you are sitting at the table with your crush 😍, while you wait for the burgers 🍔, you can spend that time admiring how awesome, cute and smart your crush is ✨😍✨.
While waiting and talking to your crush 😍, from time to time, you check the number displayed on the counter to see if it’s your turn already.
Then at some point, it finally is your turn. You go to the counter, get your burgers 🍔 and come back to the table.
You and your crush 😍 eat the burgers 🍔 and have a nice time ✨.
Imagine you are the computer / program 🤖 in that story.
While you are at the line, you are just idle 😴, waiting for your turn, not doing anything very “productive”. But the line is fast because the cashier 💁 is only taking the orders (not preparing them), so that’s fine.
Then, when it’s your turn, you do actual “productive” work 🤓, you process the menu, decide what you want, get your crush’s 😍 choice, pay 💸, check that you give the correct bill or card, check that you are charged correctly, check that the order has the correct items, etc.
But then, even though you still don’t have your burgers 🍔, your work with the cashier 💁 is “on pause” ⏸, because you have to wait 🕙 for your burgers to be ready.
But as you go away from the counter and sit at the table with a number for your turn, you can switch 🔀 your attention to your crush 😍, and “work” ⏯ 🤓 on that. Then you are again doing something very “productive” 🤓, as is flirting with your crush 😍.
Then the cashier 💁 says “I’m finished with doing the burgers” 🍔 by putting your number on the counter’s display, but you don’t jump like crazy immediately when the displayed number changes to your turn number. You know no one will steal your burgers 🍔 because you have the number of your turn, and they have theirs.
So you wait for your crush 😍 to finish the story (finish the current work ⏯ / task being processed 🤓), smile gently and say that you are going for the burgers ⏸.
Then you go to the counter 🔀, to the initial task that is now finished ⏯, pick the burgers 🍔, say thanks and take them to the table. That finishes that step / task of interaction with the counter ⏹. That in turn, creates a new task, of “eating burgers” 🔀 ⏯, but the previous one of “getting burgers” is finished ⏹.
Now let’s imagine these aren’t “Concurrent Burgers”, but “Parallel Burgers”.
You go with your crush 😍 to get parallel fast food 🍔.
You stand in line while several (let’s say 8) cashiers that at the same time are cooks 👩🍳👨🍳👩🍳👨🍳👩🍳👨🍳👩🍳👨🍳 take the orders from the people in front of you.
Everyone before you is waiting 🕙 for their burgers 🍔 to be ready before leaving the counter because each of the 8 cashiers goes and prepares the burger right away before getting the next order.
Then it’s finally your turn, you place your order of 2 very fancy burgers 🍔 for your crush 😍 and you.
You pay 💸.
The cashier goes to the kitchen 👨🍳.
You wait, standing in front of the counter 🕙, so that no one else takes your burgers 🍔 before you do, as there are no numbers for turns.
As you and your crush 😍 are busy not letting anyone get in front of you and take your burgers whenever they arrive 🕙, you cannot pay attention to your crush 😞.
This is “synchronous” work, you are “synchronized” with the cashier/cook 👨🍳. You have to wait 🕙 and be there at the exact moment that the cashier/cook 👨🍳 finishes the burgers 🍔 and gives them to you, or otherwise, someone else might take them.
Then your cashier/cook 👨🍳 finally comes back with your burgers 🍔, after a long time waiting 🕙 there in front of the counter.
You take your burgers 🍔 and go to the table with your crush 😍.
You just eat them, and you are done 🍔 ⏹.
There was not much talk or flirting as most of the time was spent waiting 🕙 in front of the counter 😞.
In this scenario of the parallel burgers, you are a computer / program 🤖 with two processors (you and your crush 😍), both waiting 🕙 and dedicating their attention ⏯ to be “waiting on the counter” 🕙 for a long time.
The fast food store has 8 processors (cashiers/cooks) 👩🍳👨🍳👩🍳👨🍳👩🍳👨🍳👩🍳👨🍳. While the concurrent burgers store might have had only 2 (one cashier and one cook) 💁 👨🍳.
But still, the final experience is not the best 😞.
This would be the parallel equivalent story for burgers 🍔.
For a more “real life” example of this, imagine a bank.
Up to recently, most of the banks had multiple cashiers 👨💼👨💼👨💼👨💼 and a big line 🕙🕙🕙🕙🕙🕙🕙🕙.
All of the cashiers doing all the work with one client after the other 👨💼⏯.
And you have to wait 🕙 in the line for a long time or you lose your turn.
You probably wouldn’t want to take your crush 😍 with you to do errands at the bank 🏦.