The Vtiger Google sync package combines the Vtiger Google contact sync and the Vtiger Google calendar sync.  This gives you:

• The convenience of having your contacts from Vtiger automatically added to your Google Contacts.  And it syncs from Google to Vtiger.
• Google takes care of getting your contacts into your phone so you can easily dial your leads/clients and know when they are calling you.
• The convenience of having your appointments from Vtiger automatically added to your Google Calendar.  And it syncs from Google to Vtiger.
• Google takes care of getting your Google Calendar synced into your phone so you can see your appointments when you are on the road.  Also, you can add appointments in your phone and have them appear in vtiger a few minutes later.
• Most users set the sync to run automatically, but you can run it manually too.