There are two ways to change what you've entered: open a record's edit form with the pencil icon, or click a value in a list and change it right there. Lists like order statuses, invoice items and groups use the second way.

Edit a Record
Customers, contacts and users have a pencil icon next to their name. Click it, change the fields and click the button at the bottom of the form (for example Update customer).
Edit a Value in a List
- Point at the value: it's highlighted when you can change it.
- Click it. A field opens with the current value selected.
- Type the new value, or pick it from the menu for a choice like Yes or No.
- Press Enter to save, or Esc to cancel.
You can edit this way on these pages, among others:
- Order Status: status names, In Sold Ratio and In Reminder.
- Invoice Items: SKU numbers, titles and prices.
- Groups, Contact Types and Custom Fields: names.
Shared items that come with every account, marked with a lock icon, can't be changed.