All contacts are organized in contact groups (categories) to make it easy to find them. Typical groups can be "Family", "Friends", "Business", but of course you can choose any names you want. There is no limit to number of groups.
To add a new group:
This will open the following screen:
Enter a name for the new group. If the new group is business-related, check the Business box on the left. The difference between Business and Personal group types is just convenience in editing: when you open a contact from business-related group, it will always be opened on the Business page, otherwise it will be opened on the Personal page by default.
To rename group:
To delete group:
ALL CONTACTS is not a group but the top level of group classification, and it cannot be deleted.
To move contacts from one group to another, select one or more contacts from the list, right click to open a popup menu, and select the desired group from the option "Move Contact to..."
To select a number of contacts from the list, click the first contact with left mouse button, then drag the mouse up or down, holding down the left mouse button. To select contacts in random order, press and hold the Ctrl button, then select desired the contacts with the left mouse button.