1. Hard quotas prevent users from writing data to disk. With hard quotas, the utility automatically limits the user's disk space for you, and no users are granted exceptions. Once users are about to reach their quota, they come to you for help.
2. Soft quotas send you alerts when users are about to exceed disk space. Unlike hard quotas, there is no physical restriction to prevent users from saving their data. However, you do get alerts and can create a corporate policy to help manage data.
Get some quick fixes for funky disk quotas
Learn about secret scripts for quota management
Read about how you can Group Policy Objects for managing disk quotas
Learn about why you should publish your disk quotas