Transactions

Transactions are great, they act like a wrapper for your SQL scripts so you open one before submitting data changes and you're able to query the affected data and you'll get responses based on the results of your changes, once you've been able to verify that only your intended change has been affected you can chose to commit or rollback your transaction.
In an Oracle database all of your scripts are executed within a transaction so it's good to make sure that you commit your changes from time to time but otherwise you're protected from miss-clicks. In an SSMS database all code is executed against the database naked so if you make a mistake it's forever, unleass you've deliberately opened a transaction.

Here's a quick example of how a transaction might be used in an SSMS database: