When you are entering a record, what you entered are automatically saved as a draft to your browser every few seconds.
This way, when your browser window are closed accidentally, you can simply load the draft by creating a new record on the same sheet. When creating a new record, the system will first check if there is a draft available. If a draft is available, it will first ask you if you would like to load this draft. You can choose to create the new record using the last draft or clear the draft to create a new record from scratch.