So in Vuejs, what is the difference between the two below?

1. Is it more advisable to do the first one?
2. Is it advisable to use the second one for other properties (methods, computed, watch, etc)?
3. What are the effects of using the second one for creating the properties?

Thank you for any input!

<template>
</template>

<script>

export default {
    data() {
      return {
      .........
      }
    },

</script>

<script>

let data = {
    .....
}

export default {
  data() {
    return data
  },
      
 </script>