The most fundamental element in Scrum is the product backlog.
The product backlog is created to reveal the product, which can be anything that provides value to its users. This could be a computer, a car, a mobile app, or a video game. As the benefit of the product increases, so does its value.
For instance, if you purchase a new smartphone that allows you to do most of your work without using your computer, you gain more freedom and flexibility. You're willing to pay the phone's price because it adds value to your quality of life.
Now, let's talk about the backlog.
The Product Backlog is a list of requirements that need to be completed before the product can be delivered. It contains unfinished tasks related to the product, much like a To-Do list.
For instance, if you're planning a vacation, you might create a to-do list with items such as:
Deciding where to go.
Booking a flight.
Requesting time off from work.
Shopping for the trip.
Processing your passport.
Booking a hotel.
None of these tasks have been completed yet. They are listed together as works in progress.
However, it's important to rank these items in the order that they need to be completed. For example, you cannot book a flight before you know whether you can take time off from work. You also cannot book a hotel before you know where and when you're going.
It's essential to define the content of each item in the backlog and reduce uncertainties through negotiation. This is called transparency. Sometimes, it may be necessary to elaborate on an item in the backlog further. This is called refinement.
Throughout the project, it's important to check whether each item in the backlog has been completed as expected. This is called audit or inspection. During these audits, deficiencies may arise, or unexpected situations may occur. In such cases, it may be necessary to adapt and change the plan quickly.