SPField.Type property & FEW ENUMERATION & LINKS

SPField.Type property :   https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfield.type.aspx

SPFieldType enumeration:  https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfieldtype.aspx  

SPRichTextMode enumeration:  https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.sprichtextmode.aspx

Search Enumeration in first link for All type of enumeration.