Each item that your quote document contains, be it a product, a text item or a Sum Discount, is stored as a record in its own object as a so-called Position (sf42_quotefx__SF42_GenLineItem__c).
You can find it as a related list at the respective quote:
Systematics
A Quote Line Item contains all the information of the element, from the calculation columns to the position in the quote and the CSS class. Each element is assigned an Object-Type (sf42_quotefx__SF42_QuoLI_Typ__c) to distinguish the individual element types from each other:
Type
Quote items
1
Header
2
Footer
3
Text Area
4
Product
5
Spacer
6
Horizontal Line
7
Sub Total
8
Total Net
9
Total Gross
10
VAT
11
Group Total Net
12
Group Total Gross
13
Page Break
14
Product Details
15
Product Overview
16
Sum Discount
17
Signature
18
Image
19
Column Heading
20
Price Rebate
21
Heading 1
22
Heading 2
23
Heading 3
Quote Line Items and Opportunity Products
When the quote is synchronized to the opportunity, Opportunity products are created from type 4 (Products) and type 16 (Sum Discount or related discount product) items and the field values from the Quote Line Item are written to the corresponding fields of the Opportunity product.
Using the default Service Date column (field sf42_quotefx__SF42_QuoLi_ServiceDate__c on the Position object), you can sync the date information of an opportunity product to the Quote Editor, edit or reset it there, and write it back to the Opportunity product.