There are lots of benefits to using Google forms to collect information from students, but the primary reason for me is that I can see at a glance how they're doing: how much do they understand? What don't they understand? What needs to be gone over again?
The old-school alternative is collecting dozens of separate pieces of paper and reviewing and grading each quiz. I end up with an idea of what they know or still need help with, but without careful, time-consuming perusal of the responses plus taking notes, it's difficult to tackle each student's individual needs.
Input to Google forms provides me with a chart with each student's responses listed down columns, making it very easy to address any misunderstandings. This is simply better instruction.
Now, Google improves how we visualize the input to forms with a summary showing total responses received, a bar chart for multiple choice responses, and other useful break-outs. You can customize the visual output and publish it with a link from your website, so all your students can see how they measured up to the rest of the class.
getting to forms from docs menu
call forms anything you like, just call them
poetry out loud