how does nested loop works in js code example

Example 1: nested loops javascript

// Basic Javascript Nested Loop / 2D Array

for (var x = 0; x < 10; x++) {
	for (var y = 0; y < 10; y++) {
    	console.log("x: " + x + ", y: " + y);
    }
}

Example 2: javascript nested loop

for (let exercise = 1; exercise <= 3; exercise++) {
   console.log(`---------- Starting exercise ${exercise}`)

   for (let rep = 1; rep <= 6; rep++) {
      console.log(`Exercise ${exercise}: Lifting weight repetitition ${rep}`);
   }
}