Party / Account structure in Trading Community Architecture.

1. What Is A Party?
One of the most important things to understand about the TCA model is that  the concept of “customer” is separated into two layers:
The Party layer and the Account layer
When CRM applications refer to “Customer” they are referring to the Party Layer. On the other hand, when ERP applications refer to “Customer” they are referring  to the Account Layer. Thus, confusion arises because both are using the word “Customer” to refer to two different things.
Party Layer
The Party layer consists of the Party itself, and the attributes of the  Party (such as the Party's addresses and contacts). A Party is defined as an entity that can enter into a business relationship. A Party can either be a Person or an Organization.
Examples of Parties:
Legacy Communications, Inc. (Organization)
University of California (Organization)
Girl Scouts of America (Organization)
Jim Johnson (Person)
Parties may have one or more addresses, and each address may have one or more uses (e.g., Bill To, Ship To, etc.). Additionally, Parties may have one or more contacts. Contacts are created by linking two Parties together via a Relationship (e.g., Jim Johnson Contact of Legacy Communications, Inc). It is important to note that the Party Layer can exist independently
without the presence of a corresponding Account Layer.
Account Layer
The Account layer consists of the Account and the Account attributes (such as the Accounts addresses and contacts). An Account is a financial roll-up point for a Party that defines the customer relationship between a Party and the implementing organization. Orders and invoices, for example, are created and processed at the Account layer, not the Party layer.
The Account layer cannot exist without a corresponding Party layer. Accounts must have one and only one owner, which must be a Person Party or and Organization Party. It is the Account owner that is financially responsible for the Account.
To illustrate this, think of a credit card as an account. A credit card cannot exist without a Person to own it and be financially responsible for it. However, a Person can exist without a credit card.
If the entire E-Business Suite is used, the Party layer is usually created first in CRM, and then the Account layer is added when it becomes necessary. In many cases, the Account layer is added when a Party wishes to place an order.  When an Account is created, it must be linked to one and only one Party. This Party is the Account owner.
Once an Account is created, Addresses can be defined for the Account. Account Address must have a corresponding Party Address in order to exist. The corresponding Party address must be associated to the Party that owns the Account. Account Addresses are a subset of Party Addresses. Similarly, an Account Contact must first be defined as a Party Contact for the Party
that owns the Account. Party Contacts are defined through Relationships.


2. What Is The Difference Between A Party and A Customer Account?

A party is an entity that can enter into business and can be of the type Organization or Person. A party exists separately from any business relationship that it enters in to with another party. Information about a party such as addresses and contacts can be shared with the customer accounts of the party. For example, Vision Distribution could be a party within your trading community.
A customer is an organization or person with whom you have a selling relationship. This selling relationship can result from the purchase of products and services or from the negotiation of terms and conditions that provide the basis for future purchases. For example, a division of Vision Distribution could become one of your customers.
A customer account represents the business relationship that a party can enter in to with another party. The account has information about the terms and conditions of doing business with the party. For example, you could open a commercial account for purchases to be made by Vision Distribution for its internal use and a reseller account for purchases made by Vision Distribution for sales of your products to end–users .
You can create multiple customer accounts for a party to maintain information about categories of business activities. For example, to track invoices for different types of purchases, you can maintain an account for purchasing office supplies and another account for purchasing furniture.
You can also maintain multiple customer accounts for a customer that transacts business with more than one line of business in your organization. You maintain separate customer profiles, addresses, and contacts for each customer account.
What is the difference between a Person and an Organization when setting up a Customer Account.
When setting up a customer in AR, you have the option of selecting if the customer is an Organization or a Person.
Select Person if the customer is an individual. This option is available as a setup when using the CRM products. If you have CRM products installed you may select the type Person. The Customer Standard Form will then display fields for entering Person information as it pertains to an individual in many CRM applications.
All Customers in the ERP applications are of the type Organization. The Customer Standard Form will then display fields for entering Organization information for setting up customers in the ERP applications.
In the above setup the Person setup will be reflected in the Person information tables in the HZ module. The “Organization” information will go against the HZ organization information tables.
When searching on an Organizations, the customer type of Person will never show up in the Match results and vice versa.

3. What Is The Difference Between A Party Site And A Party Address

A party site is the location where a particular party is physically located. Every party has only one identifying address, but a party can have multiple party sites. A customer's address is a party site used in the context of a customer account for billing, shipping, or other purposes. For example:  The customer may have a billing site, a shipping site etc.
4. What Is An Identifying Address?

You can designate one address per party as an Identifying Address. A party can have multiple party sites, but each party has one identifying address. The identifying address is used as the default search criteria in the database.
5. What Is A Party Id?

This is a unique number that identifies a party
6. What Is A Site Number?

This is a unique number that identifies a location.
7. In Release 11.5 Customer form, why Doesn't The First Customer Have An Address In The Find Results Window?

The Match Results window displays both Party and Account information.
Rows that are flush to the left, with a blank Customer Number field are the Party Records.
Rows underneath the Party Record, that are indented to the right, and contain a value in Customer Number field are Accounts.
The use of indentation is a graphic way of illustrating that the Accounts fall under the Party. When querying for customers that return multiple match results, this format makes it easier to identify whether you are looking at a Party or an Account.