How to get a form field to allow additional values? I need to have a way to allow for multiple values to be used for a field.

For example,

Someone has school name(s), and the form description says, "Add your schools here."

I add a school, press a button for an additional, another text field appears, etc.

I know I have seen this before, but I cannot seem to find it anywhere.  How do I do this?

I thought it might be this module(s):  

https://www.drupal.org/project/field_collection

https://www.drupal.org/project/webform_addmore

How to add additional &quot;items&quot; on a webform in Drupal 7

But I'm not sure.  I thought it was built into Drupal webforms.
If you want to allow a field to get multiple values.you need to edit the field and allow the numbers of values to unlimited.
Suppose you want to allow multiple images to upload in Article content type.

1)Go to Administration » Structure » Content types » Article » Manage fields 
2)Edit the field and under field settings,choose the values to unlimited or number of values you want a user can upload.
See the similar in screenshot url below.
https://www.evernote.com/shard/s496/sh/15655bf1-104c-40ed-ab26-bc6da6ebe7a5/bd1bce151edec9956746845474f3ba95