Write short note on the following:

(a) HTTP

(b) Bandwidth

(c) Bluetooth

(d) DNS

(e) Data transfer rate

(a) HTTP — HTTP stands for HyperText Transfer Protocol, which is the primary protocol used to access the World Wide Web. It is a request-response protocol (also called client-server) that runs over TCP. HTTP facilitates access to hypertext from the World Wide Web by defining how information is formatted and transmitted, and how web servers and browsers should respond to various commands.

For example, whenever we enter the URL http://www.ncert.nic.in in a browser, it sends an HTTP request to the web server where ncert.nic.in is hosted. The HTTP response from the web server fetches and sends the requested web page, which is then displayed on the browser.

(b) Bandwidth — Bandwidth of a channel is the range of frequencies available for the transmission of data through that channel. The higher the bandwidth, the higher the data transfer rate. Bandwidth is calculated as the difference between the maximum and minimum frequencies contained in the composite signals, and it is measured in Hertz (Hz).

(c) Bluetooth — Bluetooth is a short-range wireless technology used to connect devices like mobile phones, mouse, headphones, keyboards, and computers wirelessly over short distances. It enables tasks such as printing documents with Bluetooth-enabled printers without the need for physical connections. These devices utilize a low-cost transceiver chip that operates within the unlicensed frequency band of 2.4 GHz for data transmission and reception. Bluetooth devices can communicate within a range of 10 meters, achieving speeds of 1-2 Mbps. The technology allows up to 255 devices to form a network, with 8 devices capable of simultaneous communication while others remain inactive until prompted by the master device.

(d) DNS — DNS, known as the Domain Name System, serves as the phonebook of the Internet. It provides a character-based naming system for servers, allowing users to access websites using easy-to-remember domain names like google.com instead of numeric IP addresses such as 8.8.8.8. DNS is essential for internet navigation as it translates domain names into IP addresses, enabling seamless communication and resource access across the web.

(e) Data transfer rate — Data transfer rate is the number of bits transmitted between source and destination in one second. It is also known as bit rate. It is measured in terms of bits per second (bps). The higher units for data transfer rates are:
1 Kbps = 2¹⁰ bps = 1024 bps
1 Mbps = 2²⁰ bps = 1024 Kbps
1 Gbps = 2³⁰ bps = 1024 Mbps
1 Tbps = 2⁴⁰ bps = 1024 Gbps