what does funtion do in javascript code example

Example 1: functions in javascript

function name( parameter1 ,parameter 2,..)  //name signifies funcname
{
  
}

Example 2: How to create a function in javascript

function addfunc(a, b) {
  return a + b;
  // standard long function
}

addfunc = (a, b) => { return a + b; }
// cleaner faster way creating functions!