Determine upgrade approach (SharePoint Server 2010)

Before you run any process to upgrade from Microsoft Office SharePoint Server 2007 to Microsoft SharePoint Server 2010, you have to determine which upgrade approach to take. Use the information in this article to help compare the pros and cons for each approach and to review information about special cases that might influence your approach.

https://technet.microsoft.com/en-us/library/cc263447.aspx