A JS question, please answer - outside the definition of variables, function parameters, change variables within the function

This answer quotes ChatGPT

In this code, the first console.log outputs "abc" because data was assigned "abc" before fun was called. Then, the fun function is called, taking data, which is "abc". Inside the fun function, concatenate data with the string "xyz" to produce a new string "abcxyz". However, this does not change the original data variable, because strings are immutable in JavaScript. So, when fun finishes, data is still "abc". So, when the second console.log is called, the output value is still "abc".

Because function arguments are passed based on value, the value of the data argument outside the function is not changed inside the function, so the output of the first console.log is still "abc".