The Domain Name System (DNS): The Internet’s Phonebook

The Domain Name System (DNS) is often described as the “phonebook of the Internet” because it translates human-friendly domain names into Internet Protocol (IP) addresses that computers use to locate online resources. When a user types a website address such as google.com or nytimes.com into a browser, the browser needs an IP address to establish a connection with the appropriate server. DNS performs this translation automatically, allowing people to navigate the Internet without memorizing complicated numerical addresses.

Every device or server connected to the Internet uses an IP address that enables other systems to locate it. IPv4 addresses, for example, consist of four numerical sections, while newer IPv6 addresses use much longer hexadecimal strings. Because such addresses are difficult for people to remember, DNS provides a convenient naming system. It also distributes responsibility for managing domain names by assigning authoritative name servers to individual domains and domain zones.

DNS performs several important functions. First, name translation converts domain names into IP addresses so browsers and applications can find online services. Second, email routing relies on Mail Exchange (MX) records to identify the mail servers responsible for receiving messages for a domain. Third, DNS supports network navigation, helping applications locate websites, cloud services, content delivery networks, and other Internet resources efficiently. Finally, DNS contributes to security and verification. DNS Security Extensions (DNSSEC), for example, can digitally authenticate DNS information and help prevent attackers from manipulating DNS responses. DNS itself does not provide SSL/TLS encryption, but DNS records can also support certificate issuance and other security mechanisms.

The process of finding an IP address is called DNS resolution. When a user requests a webpage, the browser or operating system first checks whether the answer is already stored in a local cache. If it is not, the request is normally sent to a recursive DNS resolver. The resolver searches for the required information, potentially contacting several types of DNS servers. A root server directs the resolver toward the appropriate top-level domain (TLD) server, such as the server responsible for .com or .org. The TLD server then identifies the authoritative name server for the requested domain. Finally, the authoritative server provides the definitive DNS record, such as the IP address. The resolver returns this information to the user’s device, allowing the browser to connect to the destination.

DNS was introduced in 1983 by Paul Mockapetris to replace the increasingly impractical HOSTS.TXT file, which had been manually maintained to map computer names to addresses. In 1984, researchers at the University of California, Berkeley developed BIND, an important early Unix implementation of DNS. The protocol was subsequently standardized and documented in major Internet standards, including RFC 1034 and RFC 1035, published in 1987.

Today, DNS is a fundamental part of Internet infrastructure. Its hierarchical and distributed design allows billions of domain names and services to operate efficiently. Although DNS usually works invisibly in the background, virtually every visit to a website depends on it, making DNS one of the essential systems that keeps the modern Internet connected and usable.
The Domain Name System (DNS): The Internet’s Phonebook

Data warehouse

The term "Data Warehouse" was first coined by Bill Inmon in 1990. According to Inmon, a data warehouse is a subject-oriented, integrated, time-variant, and non-volatile collection of data. This data helps analysts to take informed decisions in an organization.

A data warehousing is defined as a technique for collecting and managing data from varied sources to provide meaningful business insights. It is a blend of technologies and components which aids the strategic use of data.

A data warehouse is a database, which is kept separate from the organization's operational database. It possesses consolidated historical data, which helps the organization to analyze its business. However, the data warehouse is not a product but an environment. It is an architectural construct of an information system which provides users with current and historical decision support information which is difficult to access or present in the traditional operational data store.

The data warehouse (DW) acts as a central repository of information originating from one or more data sources. Data flows from transactional systems and other relational databases to the data warehouse and generally consist of structured, semi-structured, and unstructured data. This data is loaded, processed and consumed on a regular basis.

The main features of data warehousing can be summarized as follows:
*Easy access to nonskilled computer users.
*Data integration based on a model of the enterprise.
*Flexible querying capabilities to take advantage of the information assets.
*Synthesis, to enable targeted and effective analysis.
*Multidimensional representation to give the user an intuitive and handy view of information.
*Correctness, completeness, and freshness of information.

There are the three types of data warehouse applications.
*Information Processing – A data warehouse allows to process the data stored in it. The data can be processed by means of querying, basic statistical analysis, reporting using crosstabs, tables, charts, or graphs.
*Analytical Processing – A data warehouse supports analytical processing of the information stored in it. The data can be analyzed by means of basic OLAP (online analytical processing) operations, including slice-and-dice, drill down, drill up, and pivoting.
*Data Mining - Data mining supports knowledge discovery by finding hidden patterns and associations, constructing analytical models, performing classification and prediction. These mining results can be presented using visualization tools.

Data warehouse technologies are successfully used:
• Trade Sales and claims analyses, shipment and inventory control, customer care and public relations
• Craftsmanship Production cost control, supplier and order support
• Financial services Risk analysis and credit cards, fraud detection
• Transport industry Vehicle management
• Telecommunication services Call flow analysis and customer profile analysis
• Health care service Patient admission and discharge analysis and bookkeeping in accounts departments
Data warehouse

What are the functions of business intelligence?

The most well-known definitions of business intelligence is “The right information to the right person at the right time in the right way.”

Intelligence involves knowing information about competitors, such as their profitability and turnover rate. The most important thing to gain from intelligence is knowledge of customers and potential customers.

Business intelligence technologies provide historical, current and predictive views of business operations. Common functions of business intelligence technologies include
*reporting
*online analytical processing
*analytics, data mining
*process mining
*complex event processing
*business performance management
*benchmarking
*text mining
*predictive analytics
*prescriptive analytics

Business intelligence system queries a data source, uses techniques such as online analytical processing and data mining to analyze information in the source and reports the results of its work.
What are the functions of business intelligence?

Intelligent Transportation System (ITS)

Intelligent Transportation System is an evolving scientific and engineering discipline whose primary goal is to minimize the travel time of all travelers and merchandise while ensuring safety, through fair distribution of variable resources, especially under the scenario of increasing travel speeds, a significantly large number of travelers, and a high demand for precise and timely information by travelers.

The system provides support to improve services in transportation system operations, such as traffic management, commercial vehicle operations, transit management and information to travelers. It could lead to capacity improvements with same physical infrastructure by enhancing the efficiency of the transportation system.

Intelligent Transportation System combines high technology and improvements in information systems, communications, sensors and advanced mathematical methods with the conventional world of surface transportation infrastructure.

It has the potential to improve traffic flow by reduction congestion, improve air quality by reducing pollution and travel delay and improve safety by providing advance warning of probable crash situations and minimizing the effects of environmental, highway and human factors that contribute to crashes.

It can also foster economic growth in a region by improving mobility and reducing fuel consumption.
Intelligent Transportation System (ITS)

Spreadsheet software

A spreadsheet is a group of values and other data organized into rows and columns, similar to the ruled paper worksheets traditionally used by bookkeepers and accountants. The software permits businesspeople to manipulate decision variables and determine their impact on such outcomes as profits and sales.

Today there are many options available for those who want to use spreadsheets. There are the most popular and well known spreadsheet programs – namely Microsoft Excel, Lotus 1-2-3 and WordPerfect Office’s Quattro Pro. Many spreadsheets include formulas that are used to compute calculations based on data entered into the spreadsheet.

All formula results are automatically updated whenever any changes are made to the data.

Most spreadsheet programs include some types of charting or graphing capability. Because the data to be included in many business charts is often already on a spreadsheet, using that program’s charting feature eliminates reentering that data into another program.

Spreadsheets aren’t just for accountants or finance professional: people in other business areas such as marketing, human resources and production rely on spreadsheet programs as well.

Increasingly, there are Web-based spreadsheet programs available. All needed is an internet connection and a browser. The user simply goes to the provider’s web site and works on a spreadsheet online.

Although they are used less commonly to create web pages, many spreadsheet programs include the option to save the current worksheet as a web page, and hyperlinks can be inserted into worksheet cells.
Spreadsheet software

Database Management system

A database is a well-organized collection of data that are related in a meaningful way, which can be accessed in different logical orders.

Some commonly used databases are: address book, library catalogue, telephone directory and stock list.

The computer program used to manage and query a database is known as a database management system. Database management system is a collection of database and DBMS utilities which are used to develop applications to satisfy the requirements of user by application developers under the supervision of database administrator. Database management system is software that is helpful in maintaining and utilizing a database.

The main objective of database management systems are data availability, data integrity, data security and data independence.

Database management systems must facilitate the major functions including:
*Defining of database schema
*Manipulation of database
*Sharing of database
*Protection of database
*Database recovery
Database Management system