Explanation
The Scrum Guide states that "The Daily Scrum is a 15-minute time-boxed event for the Development Team to synchronize activities and create a plan for the next 24 hours."1 The Daily Scrum is a quick and simple planning meeting designed to keep everyone in the loop with how other team members are getting on. It ensures that team members are fully aligned with each other and on track to hit the Sprint Goal.
References:
* 1: The Scrum Guide2, page 11
* 2: The Scrum Guide

The Scrum Guide states that " By the end of the Sprint Retrospective, the Scrum Team should have identified improvements that it will implement in the next Sprint. Implementing these improvements in the next Sprint is the adaptation to the inspection of the Scrum Team itself. " 1 This means that the Scrum Team may add the high priority process improvements to the Sprint Backlog for the next Sprint, as part of their plan to deliver the Increment and achieve the Sprint Goal. The Sprint Backlog is owned and managed by the Developers, who can update it throughout the Sprint as more is learned.1
1: The Scrum Guide2, page 16
2: The Scrum Guide

Developers are self-managing, which means that they decide how much work they can do in a Sprint, and how they will do it1. They manage the Sprint Backlog, which is the plan for how the Developers will achieve the Sprint Goal, and the single source of truth for the work to be done in the Sprint2. The Developers create and update the Sprint Backlog throughout the Sprint as more is learned[3][3] . The other options are not managed by the Developers, but by the Product Owner or the Scrum Team as a whole. The Product Owner is accountable for ordering the Product Backlog, which is an ordered list of everything that is known to be needed in the product4. The Product Owner also decides when to release the product, based on the value, risk, and stakeholder feedback5. The Scrum Team collaborates on inviting the stakeholders for the Sprint Review, which is an event where the Scrum Team and the stakeholders inspect the product Increment and adapt the Product Backlog. The Scrum Team also decides the Sprint length, which is the time-box within which the Scrum Team delivers a product Increment.
1: The Scrum Guide, November 2020, p. 6
2: The Scrum Guide, November 2020, p. 10
[3][3] : The Scrum Guide, November 2020, p. 10
4: The Scrum Guide, November 2020, p. 6
5: Managing Products with Agility, Scrum.org, accessed on December 16, 2023 The Scrum Guide, November 2020, p. 13 The Scrum Guide, November 2020, p. 9

Explanation
Sprints are fixed-length events of one month or less that serve as a container for the other Scrum events and activities. Sprints have consistent durations throughout a development effort. A new Sprint starts immediately after the conclusion of the previous Sprint. There is no gap or downtime between Sprints. The second Sprint starts right after the first Sprint, regardless of the customer acceptance testing, the architectural changes, or the Product Backlog items.
References:
* The Scrum Guide
* Understanding and Applying the Scrum Framework
* Professional Scrum Product Owner™ I Certification