Virtual Reality- Reality which is virtual
It is achieved through a head-mounted display or handheld controller.Basically, it is an artificial simulation of a real-life environment or situation where we can have a real feeling of the environment that is shown in the headset screen or mobile device. It feels like we are entered inside the screen of the device.It immerses the users by making them feel like they are experiencing the situation.
Uses of Virtual Reality
- people can have a hands-on practice like flight simulation for aircraft pilots
- new bus drivers can be trained in driving skills using Virtual reality simulators. Such a training provides to safely train the driver in avoiding real-life accidents
- can tour the whole world just by sitting at one place through Virtual reality application like Google earth VR
- future of education resides in Virtual reality where students from around the world can get a real hands-on learning experience
- The future developments in field of Virtual reality are having vibration and sensation feedback for example if I traveled to Antarctica using my virtual reality device I can feel the cool temperature of Antarctica using sensation sensors attached to my body
- Youtube has also launched virtual reality videos
- Virtual amusement parks- Galactica roller coaster introduced by Alton towers in the UK
- In real we can’t build Jurassic Park but in virtual reality, we can build it
- Adult video industry
Content creation and development
- VR application creation
- they are various apps build for VR platform so developers can build their own VR apps
- Google has also introduced his own google cardboard app which contains various interesting applications
- Gaming industry has made various games based on this VR technology
- you can become an astronaut from your bedroom and learn the life of an astronaut
Some startup in field of Virtual Reality
- Discover labs- Based on learning
- Razer- gaming industry
- World Viz- Software industry
- Matterport- 3D Camera
- Decentraland- VR platform on Blockchain
Domain Name System or Server
computer communicate with each other through the internet with the help of IP(Internet protocol) address- it is a number assigned to every device connected to the computer network to uniquely identify the particular network.
IP address is long enough to remember by humans like 22.214.171.124
So to make it easier every IP address is replaced by the domain name which is simply a name easy to remember for example google.com
Domain name system resolves the conversion from domain name to IP address
for example, if we type www.google.com the DNS will automatically convert this name to its IP address at the backend
The conversion takes place by matching the domain name with the IP address which is stored in Domain name server database.
A network topology defines the way in which the computers, printers and other devices are connected.The topology plays an important role in computer networks
Physical vs logical topologies
A physical topology is how they are actually connected with wires and cables whereas a logical topology is how devices appear to be connected to the user.
Types of Topologies
Bus Topology-In this the devices are connected by a single cable which runs throughout the network.
- It works well for small networks
- Use less cable than other physical topologies
- easy to add new networks
- inexpensive to install
- if backbone breaks the whole network is down
- only limited no of devices can be included
- sharing the same cable slows down the access time
- difficult to isolate the problem
Ring Topology-In these devices are connected in a form of ring or circle.In this data flows in ring from device to device
- Single ring-Date flows only in one direction either clockwise or anticlockwise
- Dual ring-Data flows in two directions
- There is no collision
- Data packets can be travel at high speed
- no terminations are needed
- it is easier to locate problems with device or cable
- requires more cable than bus network
- a break in the cable will bring down many devices
- when adding new devices to ring, all devices are suspended from using the network
Star topology-In this network device are connected in a star shape.In this, there is the central hub to which many devices are connected.
- easy to add more devices to the network
- The failure of one cable will not break down the entire network
- The hub provides centralized management
- it is easy to find device and cable problem
- The failure of one central hub breaks down the entire network
- require more media than a ring or bus network
- cost of installation and equipment are higher than for most of the bus networks
Mesh topology– In this each device is connected to every other device.
- A mesh network offers improved fault tolerance if part of system goes down
- expensive and difficult to install
- difficult to manage
- difficult to troubleshoot
Hybrid topology– When two or more topologies are combined in a single network it is known as hybrid topology
Ping is a protocol for checking of latency between two networks
It is response time or time required in networks to communicate with each other
Basically, a device sends data packets to server or another device and receives back the data packets
It is time taken for a data packet to travel round trip
- Ping is used in checking internet speed test
- used to check the speed of data transfer in networks
- can be helpful for playing online game ping time should be minimum in case of online gaming
- for an instant response from a website ping time should be minimum but in case of downloading ping does not matter much
How to check PING time in windows
- run start and type cmd in the search bar
- open command prompt and type PING<space>Website name
- for example PING teachoutlet.com
Programmers write codes in high-level language however the computer does not understand any other language other than its own machine language of zero and one that is binary language.
Therefore it is necessary to process the High-level language into binary language so it is done by the language processors
This language processor converts the program written in assembly language into machine language
This language processor converts high-level language program into machine language(binary) by converting and executing line by line.
If there is any error in any line it reports at the same time and program execution can not resume until the error is rectified.
- For error debugging, an interpreter is useful as it reports the error at the same time.
- But once errors are removed usage of memory takes place as interpreter must always be present in memory
It also converts the High-level language into machine language(binary) but conversion method is different it converts in one go and reports all the error of program after conversion along with line numbers.
- After all, error is are removed, the program is recompiled and after that, the compiler is not needed in the memory as the object program is available
- Interpreter is much better for error removal than compiler
Firmware is basically a software type which is pre-installed in the device non volatile memory(like ROM) from the device manufacturer.
We can not change or access the firmware easily
It can be updated if the manufacturing company allow us to update.The update is for bug fixes or adding new features to the device
It can be hacked
Why it is required
- It defines the functionality of the device
- it is controlling software for modern electronic
- used to run an application program on the device
- used to protect the device from malware