"Quote Template" is a field you select when you create an opportunity. The Quote Template field allows you to define common elements required for opportunities of the same nature.
You can add as many quote templates as you need under "Settings > Opportunity > Quote Templates."
For each quote template, you can specify the following:
Payment schedule
Proposal template
Items
Labor types
The following is a screenshot of the modal for creating a new quote template.
When you select a quote template for an opportunity, the product, labor, and payment schedule are preloaded into the quotes for that opportunity. This reduces the time and effort required to build quotes.
If you want to remove or change the default items preloaded from the template, you can do so using the item addition, update, and delete options in the quote.
If you want to remove or change the labor types, go to the Quote Details view, the 3-dot menu of the quote, "Settings > Labor Types," and make the changes.
If you want to remove or change the payment schedule, go to the Quote Details view, the "Overview" section and select the "Payment Schedule" tab.
If you want to change the proposal template, change it in the Edit Proposal view.