In a synchronous programming model, things happen one at a time
This means that only one operation can be in progress at time
When you call a function that performs a long-running action, it returns only when the action has finished and it can return the result
Subsequent actions can only be run after the previous action has completed; this means that action #1 blocks action #2
JavaScript is a synchronous, blocking, single-threaded language by default
Most of the code we’ve written so far has been synchronous
Here’s an example of Synchronous code
function printLetter(letter) {
console.log(letter)
}
function printAll(){
printLetter("A")
printLetter("B")
printLetter("C")
}
printAll()
The the example above, printAll() calls printLetter() 3 times with “A”, “B”, “C” as parameters and each letter is printed out in the order in which the function was called