A couple of days ago, I had to fix a form another developer had created. The form utilised the checkbox input type which I rarely use. I came across an interesting way of storing the data which may be standard? Definitely foreign to me. If you append the array brackets [] to the end of the checkbox name section, example:

<input type="checkbox" name="colours[]" value="red">
<input type="checkbox" name="colours[]" value="blue">
<input type="checkbox" name="colours[]" value="green">

The data will be stored in an array for you to handle as you wish on the server side.