let and var in Javascript - Difference

- *`var`:*
  - Function-scoped.
  - Hoisted and initialized with `undefined`.
  - Can be re-declared within the same scope without an error.

- *`let`:*
  - Block-scoped.
  - Hoisted but not initialized (temporal dead zone).
  - Cannot be re-declared within the same scope.

For most scenarios, it's preferable to use `let` due to its block-scoping and more predictable behavior.

Certainly:

- *`var`:*
  - Function-scoped, not block-scoped.
  - Hoisted to the top of its function or global scope.
  - Allows re-declaration within the same scope.
  - Can be accessed before the declaration (due to hoisting) with an initial value of `undefined`.

- *`let`:*
  - Block-scoped, meaning it's limited to the block where it's defined.
  - Hoisted to the top of its block, but not initialized (results in a temporal dead zone).
  - Does not allow re-declaration within the same scope.
  - Provides more predictable scoping behavior, especially in loops and conditional statements.

In modern JavaScript, `let` is often preferred over `var` for its block-scoping and improved handling of variable declarations.