docs: improve commerce modules [3/n] (#9510)

Improve and add docs for Order and Payment modules

[3/n]

Closes DOCS-966
Closes #9485

www/apps/resources/app/commerce-modules/payment/payment-collection/page.mdx

@@ -4,7 +4,7 @@ export const metadata = {
 
 # {metadata.title}
 
-In this document, you’ll learn what a payment collection is and how to use it with the Cart Module.
+In this document, you’ll learn what a payment collection is and how the Medusa application uses it with the Cart Module.
 
 ## What's a Payment Collection?
 
@@ -12,15 +12,17 @@ A payment collection stores payment details related to a resource, such as a car
 
 Every purchase or request for payment starts with a payment collection. The collection holds details necessary to complete the payment, including:
 
-- The payment sessions that represents the payment amount to authorize.
-- The payments that are created when a payment session is authorized. They can be captured and refunded.
-- The payment providers that handle the processing of each payment session, including the authorization, capture, and refund.
+- The [payment sessions](../payment-session/page.mdx) that represents the payment amount to authorize.
+- The [payments](../payment/page.mdx) that are created when a payment session is authorized. They can be captured and refunded.
+- The [payment providers](../payment-provider/page.mdx) that handle the processing of each payment session, including the authorization, capture, and refund.
 
 ---
 
 ## Multiple Payments
 
-The payment collection supports multiple payment sessions and payments. You can use this to accept payments in increments or split payments across payment providers.
+The payment collection supports multiple payment sessions and payments.
+
+You can use this to accept payments in increments or split payments across payment providers.
 
 ![Diagram showcasing how a payment collection can have multiple payment sessions and payments](https://res.cloudinary.com/dza7lstvk/image/upload/v1711554695/Medusa%20Resources/payment-collection-multiple-payments_oi3z3n.jpg)
 
@@ -30,8 +32,8 @@ The payment collection supports multiple payment sessions and payments. You can
 
 The Cart Module provides cart management features. However, it doesn’t provide any features related to accepting payment.
 
-With the Payment Module, you can create a payment collection for the cart and process the payment.
+During checkout, the Medusa application links a cart to a payment collection, which will be used for further payment processing.
 
-The Medusa application creates a link between the `PaymentCollection` and `Cart` data models. It also implements the payment flow during checkout as explained in [this documentation](../payment-flow/page.mdx).
+It also implements the payment flow during checkout as explained in [this documentation](../payment-flow/page.mdx).
 
 ![Diagram showcasing the relation between the Payment and Cart modules](https://res.cloudinary.com/dza7lstvk/image/upload/v1711537849/Medusa%20Resources/cart-payment_ixziqm.jpg)