phpspec is a design tool which you can use for testing your code. No more trying to guess how to name something, or how to use something. Get better at designing your code and go home on Friday night knowing dinosaurs are not running around eating your customers.
You're always testing, the only difference is if it's manual or automatic.
Don't worry if you have no idea to start with automated testing. Together with SymfonyCasts we made a course which will show you everything, teach some of theory, and will make you laugh a time or two.
Go to the SymfonyCasts and learn how to test and design your code with phpspec.