The output of a Sprint is a usable Product Increment. "Usable" means the stakeholders can see the product working as if it were released. The increment is the verified sum of all the Product Backlog Items completed during a sprint, plus all previous increments produced in the current and past sprints. Because of this, the increment needs to be integrated with the ones produced in past sprints. It must be in usable condition, regardless of whether the Product Owner decides to release it or not. The Product Owner is responsible for deciding when to release the Product Increment.

In scrum, a product increment is whatever you previously built, plus anything new you just finished in the latest sprint, all integrated, tested, and ready to be delivered or deployed. Without a usable product increment, development teams are delaying the delivery of value and are missing opportunities to get real user feedback and adapt the product to ensure customer satisfaction. On the other hand, incremental releases allow for fast feedback, quicker innovation, continuous improvement, rapid adaptation to change, and more delighted customers.

Sprint is a short period in which a team works to produce an end deliverable. Within each sprint, there are Scrum inspect and adapt events. Also known as ceremonies, these meetings are held by the Scrum team to clarify the purpose, progress, and results of a particular sprint. There are four Scrum inspect and adapt events in total: sprint planning, daily Scrum, sprint review, and sprint retrospective.

By definition, a Sprint cannot be longer than one calendar month. Therefore any so-called Sprint of a longer duration will be invalid, and it would mean that Scrum principles are not being followed.
Note that the Agile Manifesto allows up to two months between each delivery of customer value, albeit with a preference towards shorter timescales. Iterations of greater than a month may therefore be arguably agile, although they would not be Scrum-compliant.
Also, bear in mind that Scrum Sprints must result in *potentially* releasable increments and that the time between actual releases may therefore exceed one month. However, if the release of an increment equates to the delivery of customer value, and if the release is deferred for longer than two months, then the Scrum implementation (although strictly valid) would not conform with the principles of the Agile Manifesto.
Therefore be sure to time-box Sprints to no more than one month in length, and aim to release an increment into production at least every two.

A Product Owner must be an expert in the business domain and industry. To understand customer requirements better and translate them into product requirements, a Product Owner must be well-versed in business logic as well as the technical capabilities of the product. It is a diverse role that requires a mix of several skills and experience for high performance.

If the Product Owner has this authority, he can respond to the changing needs of the customer and the marketplace. If not, he is blocked from being effective and may need approval on all Product Backlog Item decisions which causes a waste of time, by the Product Owner, and waste in the effort, by the Scrum Team.

The product owner is a technical role. You can’t become a great PO if you don’t know the ins and outs of development, design, agile framework, software development, scrum approach, and IT infrastructure. Technical skill is defined as a specialized skill that is used to perform a specific task such as programming and software development. The agile product owner must be technically sound because backlog management and prioritization are technical tasks. It can’t be done effectively if the PO doesn’t understand the development and design processes and has no knowledge of how software development works.

Product Owner’s need is almost there on all the events except Daily Scrum because Daily Scrum is a time-boxed event for the Development Team to inspect and adapt daily. When a Product Owner is not available during the Sprint, it is one of the great impediments. It will certainly affect the ability of the Development Team to come up with a “done” product increment. If there is no Product Increment at the end of the Sprint, then the Sprint Goal cannot be reached.

The definition of Done is about building the product “right,” and Acceptance Criteria is about developing the “right” product.

According to the 2020 Scrum Guide, “The entire Scrum Team is accountable for creating a valuable, useful Increment every Sprint”. The definition of Done (DoD) is designed as a checklist, and it's used to check every user story for completeness or product backlog item. In other words, DoD is made to apply to all items in the product backlog, not just a single story.

The Acceptance Criteria of a User Story consist of a set of Test Scenarios that are to be met to confirm that the software is working as expected. It:

• applies to one Story/PBI,
• is different for each story,
• is used as a way of communication for all those involved to ensure that all story requirements have been met.

Therefore the product owner is responsible for specifying acceptance criteria and user stories.