What is the difference between say and ask blocks ?

The differences between say and ask blocks are:

1. Say block is used to represent speech by sprites whereas ask block is used to prompt something to user asking for a value or response.
2. Say block displays a specific speech block in the speech bubble which appears on the screen for a specified amount of time whereas ask block provides a place for the message to be displayed and waits for the response.
3. Say block doesn't prompt the user for any response whereas ask block provides an input box where the user can type his response.
4. Say block is available under looks category whereas ask block is available under sensing category.