1, A, augmented reality (AR): is a technology that allows computer-generated virtual imagery information, combining the real world with virtual worlds, providing interaction and presenting three-Dimensional object. AR has a massive impact on the educational system. Nowadays schools use AR because it has made teaching easier by:- Giving a Better Explanation of Complex and Abstract Concepts: There is no doubt students will understand the concept better when they will visualize it in reality. Especially for the difficult topics, students will get to learn quickly with 3-dimensional model representations. - Elevating Student Engagement: AR learning provides a game field approach towards learning; which makes the lessons fun. As a result, it serves a positive impact on the students and keeps them engaged. - Helping with Practical Knowledge: Students can perform practical without any physical need for lab equipment. This is mainly helpful for professional courses like medical and engineering. Students don’t have to operate a patient practically and still can learn the process. - Being Accessible Learning: With AR apps the users can learn anytime and anywhere from their smart phones. It is the best way to replace paper books, posters, huge physical models etc. B, Virtual Reality (VR): is produced by a combination of technologies that are used to visualize and provide interaction with a virtual environment. As AR virtual reality is also being used in education but its cost more than AR but the money is nothing compared to the impact it’s going to have on teaching & learning and they are :- - - - Learn by doing: VR in education provides an experience anchor to the instruction. With VR education, learners are inspired to discover for themselves. Students have an opportunity to learn by doing rather than passively reading. Develop creativity: Having virtual reality in education helps not only for content consumption, but it’s also great for content creation. By giving students powerful tools such as Tilt Brush, you help them boost their creativity. Virtual field trips: VR technology is used to engage students in topics related to geography, history, or literature by offering a deeply immersive sense of place and time. Simply imagine geography lessons where you can visit any place on the globe, this type of experience is much more enriching than just reading about it. Emotional reaction: Visceral reactions to what we are experiencing are fundamental to forming memories. VR in education makes it easy to engage students the whole time, making experiences memorable. C, mixed reality (MR): is the merging of real and virtual worlds to produce new environments and visualizations where physical and digital objects co-exist and interact in real time. MR is more expensive than the others and it’s not widely used in education as the VR & MR because of that reason but in some places MR shown its significance by:- - - Allowing you to control your surrounding: students can touch and manipulate objects generating a greater understanding of them and that will help them a lot. Developing interaction: Students can also interact with data sets, complex formulae and abstract concepts which could be more difficult to understand through teacher’s verbal instructions. For many students, in fact, learning by doing is easier than learning by listening. Being more engaging: Mixed Reality provides a more engaging, fun and effective learning experience than the traditional educational methods. Kids are more interested in it than the traditional way of learning. Being visually learnt: Instead of reading about things, students actually see the things they’re learning about. Being able to visualize complex functions or mechanisms makes them easier to comprehend. 2, A, Bitcoin is often described as a cryptocurrency, a virtual currency or a digital currency. It is a type of money that is completely virtual. It’s like an online version of cash. You can use it to buy products and services, but not many shops accept Bitcoin yet and some countries have banned it altogether. The physical Bitcoins you see in photos are a novelty. They would be worthless without the private codes printed inside them. Each Bitcoin is basically a computer file which is stored in a 'digital wallet' app on a Smartphone or computer. People can send Bitcoins (or part of one) to your digital wallet, and you can send Bitcoins to other people. Every single transaction is recorded in a public list called the blockchain. This makes it possible to trace the history of Bitcoins to stop people from spending coins they do not own, making copies or undoing transactions. There are three main ways people get Bitcoins:- You can buy Bitcoins using 'real' money. You can sell things and let people pay you with Bitcoins. They can be created using a computer. In order for the Bitcoin system to work, people can make their computer process transactions for everybody. The computers are made to work out incredibly difficult sums. Occasionally they are rewarded with a Bitcoin for the owner to keep. People set up powerful computers just to try and get Bitcoins. This is called mining. But the sums are becoming more and more difficult to stop too many Bitcoins being generated. If you started mining now it could be years before you got a single Bitcoin. You could end up spending more money on electricity for your computer than the Bitcoin would be worth. Bitcoin is very secure every transaction is recorded publicly so it's very difficult to copy Bitcoins, make fake ones or spend ones you don't own. It is possible to lose your Bitcoin wallet or delete your Bitcoins and lose them forever. There have also been thefts from websites that let you store your Bitcoins remotely. The value of Bitcoins has gone up and down over the years since it was created in 2009 and some people don't think it's safe to turn your 'real' money into Bitcoins. B, Blockchain have three important principles decentralization, transparency and immutability and we will discuss about as follows. Decentralization: Blockchain technology does not rely on involvement by third parties or hardware, nor does it have any central control. All blockchain regular users can partake in the authentication of their data. Blockchain technology forms a network through a P2P (peer to peer) protocol. Unlike the centralized network, nodes in a P2P network have the same network power, and there is no centralized server Transparency: Blockchain technology is an open source, data is open to everyone. Anyone can query blockchain data and develop applications through a common interface. Blockchain data resources and management belong to all nodes joining the blockchain system, while entities outside the blockchain system are blocked. As a distributed general ledger technology, all data records and operations within the system are transparent to all nodes in the network. The blockchain ensures high transparency of data information through a combination of asymmetric encryption and hash encryption. The procedures, rules, and access methods of the blockchain network are public manual intervention Immutability: Each node added to the blockchain is distributed to record blockchain data, which guarantees irreversible modification of the data. Once the data information is verified and added into the blockchain, it will not be tampered. 3, Digital privacy refers to the protection of an individual's information that is used or created while using the Internet on a computer or personal device. New technologies present further challenges to privacy rights and regulations. Many technological advantages go hand-in-hand with privacy risk. And here are the three sub-related categories of digital privacy:- - Information privacy In the context of digital privacy, information privacy is the idea that individuals should have the freedom to determine how their digital information is collected and used. This is particularly relevant for personally identifiable information. The concept of information privacy has evolved in parallel to the evolution of the field of Information Technology (IT). The rise of networking and computing led to the dramatic change in the ways of information exchange. The baseline for this concept was put forward in the late 1940s, and the third era of privacy development began in the 1990s.The European Union has various privacy laws that dictate how information may be collected and used by companies. Some of those laws are written to give agency to the preferences of individuals/consumers in how their data is used. In other places, like in the United States, privacy law is argued by some to be less developed in this regard. By example, some legislation, or lack thereof, allow companies to self-regulate their collection and dissemination practices of consumer information. - Communication privacy In the context of digital privacy, communication privacy is the notion that individuals should have the freedom, or right, to communicate information digitally with the expectation that their communications are secure meaning that messages and communications will only be accessible to the sender's original intended recipient. However, communications can be intercepted or delivered to other recipients without the sender's knowledge, in a multitude of ways. Communications can be intercepted directly through various hacking methods, such as the man-in-the-middle attack (MITM). Communications can also be delivered to recipients unbeknown to the sender due to false assumptions made regarding the platform or medium that was used to send information. For example, the failure to read a company's privacy policy regarding communications on their platform could lead one to assume that their communication is protected when it is in fact not. Additionally, companies frequently have been known to lack transparency in how they use information, which can be both intentional and unintentional. Discussion of communication privacy necessarily requires consideration of technological methods of protecting information/communication in digital mediums, the effectiveness and ineffectiveness of such methods/systems, and the development/advancement of new and current technologies. - Individual privacy In the context of digital privacy, individual privacy is the notion that individuals have a right to exist freely on the internet, in that they can choose what type of information they are exposed to, and more importantly, that unwanted information should not interrupt them. An example of a digital breach of individual privacy would be an internet user receiving unwanted ads and emails/spam, or a computer virus that forces the user to take actions, which otherwise they would not. In such cases, the individual does not exist digitally without interruption from unwanted information; thus their individual privacy has been infringed upon. Some internet users proactively work to ensure information cannot be collected; this is the practice of attempting to remain anonymous and defend computers, servers, mobile, devices, electronic systems, and data from malicious attacks and it’s called cyber security. There are many ways for a user to stay anonymous on the internet using cyber security, including onion routing, antivirus and antispyware programs, anonymous VPN services, probabilistic anonymity, deterministic anonymity and firewall that block unauthorized access to a network.