What is the difference between Hard Type and Soft type and what are Modeled Attributes, Standard Attributes, Global Attributes

I'll give it my best shot.

• Hard Type attributes are pre-programmed into the system by PTC, like Part Number and Description. These are also known as Standard Attributes in the Type and Attribute Manager. And to be honest with you they are an absolute ridiculous pain to mess with; they can usually only be fiddled with on the server with clumsy functions from the Shell command.
• Not quite sure what you mean by Modeled Attributes but I'm going to guess you mean Alias and Calculated attributes. Alias attributes are a "soft-type" read-only copy of an attribute on something else; one personal example of using this, we have a Proposed Solution field on our Change Requests that does not normally exist on Change Notices but we did want the information, so with an Alias attribute on the Change Notice I put a read-only copy of Proposed Solution there. They can be a little fiddly to work with because of the Mapping you have to do. For the example I gave above, the Mapping line was: theChangeOrder2@wt.change2.AddressedBy2~theChangeRequest2^wt.change2.WTChangeRequest2~proposedSolution. As for Calculated attributes we've never used them but from what I've read they're supposed to be a mathematically or programmatically auto-calculated value based on a function you define for several attributes on the object
• Soft Type attributes, or Global attributes, are the key attribute to use for customization. You can easily define them in the Type and Attribute Manager without having to dive into the server and they can handle pretty much any data type you can think of except for a role picker. Raw text fields, limited pick lists, voting toggle switches...very, very handy and easy to work with.

Hope that helps,

Daryl