Difference Between Data and Signal

Slno Data Signal
1. Data is what we need to sent through a medium.Data is being carried from one place to another. Signal is what we can sent.Signals are used to carry information from one device to another.
2. Data is raw form, or unprocessed form. The signal is electromagnetic form of data that is used to transfer from one location to another.
3. The data can be either in analog form or digital form. The signal can be either analog or digital in nature.The analog signal refers to a continuous stream of data, whereas digital signal is in discrete forms.
4. Data can not be transmitted as it is. It must be converted into respective signals/electronic form.  A signal can be transmitted via a medium because it is in electromagnetic form.
5. It represents ‘values of qualitative or quantitative variables’, belonging to a set of items.It may be in the form of numbers, letters, or a set of characters.  It is electronic in nature. 
6. It is often collected via measurements/various sources. It is generally created from data.


Difference Between Analog Signal and Digital Signal

Slno Analog Signal Digital Signal
1. An analog signal is a continuous form of wave that changes over time to time. A digital signal is a discrete form of signal that carries information in bit/binary form.
2. It is graphically represented by a continuous sine wave. It is graphically represented by a discrete square wave.
3. An analog signal is normally described by the physical terms amplitude, frequency, and phase. Here, information is translated into electric pulses of varying amplitude. A digital signal is normally described by electronic term bit rate and bit intervals.
4. Analog signal has no fixed range. Digital signal has a fixed range i.e. 0 and 1.
5. It is generated by physical measurements. It is generated by digital modulation.
6. Poor quality data. Better quality data.
7. Found in only analog devices. Found Only in digital electronic devices.
8. An analog signal is more close to distortion. A digital signal is less close to distortion.
9. An analog signal transmit data in the form of a wave. A digital signal carries data in the binary form i.e. 0 and 1.
10. Consumes high power during processing. Consume less power during processing.
11. Noise affected signal i.e. analog signals produce too much noise. Noise immune signal i.e. digital signals do not produce noise..
12. Low cost and normally portable.
High cost and not easily portable.
13. Take time to be stored.
Easily stored.
14. More accuracy due to continuous. Less accuracy due to discrete.
15. Examples are – Animal’s/Natural voice  such as human voice, analog Thermometer, Analog phones. Examples are – Signals in Computers, optical drives, digital camera, digital phones and  several other electronic devices.




Difference Between Encoding and Modulation

Slno Encoding Modulation

In computer network, Encoding is a process of converting digital or analog data to digital signal. In other words, encoding is the process by which the data is converted into digital format for efficient transmission or storage.

Encoding = Digital/Analog Data —–> Digital signal.

In computer network, modulation is process of  converting digital or analog data to an analog signal. In other words, modulation is the process of converting information (signals or data) to an electronic or optical carrier, so that it can be transmitted to comparatively large distance without getting affected by noise or unwanted signals.

Modulation = Digital/Analog data ——-> Analog signal.

2. The way in which the computer data is represented.
Modulation is the method to send data up to large distance without (least) getting affected by noise or unwanted signals.
3. Encoding is used to ensure efficient transmission and storage of data. Modulation is used to send the data/signals to a long way.
4. Encoding is mainly used in computers (to convert the format of the data), in other multimedia applications and also in common operation done in most wireless communication systems. Modulation is used in communication mediums such as telephone lines and optical fibers.
5. Encoding is about assigning different binary codes according to a particular suitable algorithm Modulation is about changing the properties of one signal value according to certain properties (Amplitude, Frequency, or Phase) of another signal.
6. Encoding is about representing a signal. Modulation is about changing a signal.

NB : (In computers, Encoding is the process of putting a sequence of characters (letters, numbers, punctuation, and certain symbols) into a specialized format for efficient transmission or storage. Decoding is the opposite process i.e. the conversion of an encoded format back into the original sequence of characters).

——-  X  ——

Difference Between SMTP and POP3

Slno. Similarities
01. Both are Application layer protocols.
02. Both are related to e-mail transactions.
03. Both are standard protocols.
04. They send or receive e-mail using TCP/IP connection.
05. Both use well-known type of port number.
01. SMTP stands for ‘Simple Mail Transfer Protocol’. POP3 stands for ‘Post Office Protocol revised version 3’.
02. It was first proposed in 1982. It was first proposed in 1988. Before it, sending and receiving of e-mail was done by smtp.
03. Transmit email messages over the Internet i.e. handles outgoing mails. receives email messages from users mail server i.e. handles incoming mails.
04. It is considered as push protocol. It is considered as pull protocol.
05. It is used to send the e-mail efficiently and reliably over the internet from the client (applications)to remote server. It is used to download the e-mails from remote server to local client(account applications).
06. It works on port no. 25 (default) (in configured special case it is 465 & 587). It works on port no. 110 (default) and port no. 995 when used with security application SSL/TLS.


Difference Between Circuit Switching and Packet Switching

Slno Circuit Switching Packet Switching
1. It was Initially designed for Voice communication. It was Initially designed for Data Transmission.
2. It is inflexible, because once a dedicated physical path (point to point) is set between source and destination as a single connection line, all the data is transmitted through the same path. It is flexible, because each data packet may take a different route to reach their destination through a dynamic logical path.
3. It supports connection oriented services i.e. a dedicated path is established between source and destination before the transmission occurs. It supports connection less services i.e. a dynamic route is decided for each packet while transmission.
4. It is not a store and forward technique. It is a store and forward technique i.e. data is stored temporarily at intermediate nodes.
5. Here, transmission of the data is done by the source. Here, transmission of the data is done not only by the source, but also by the intermediate routers.
6. Data itself doesn’t carry the signalling/control information and moves on its own.
Each data packet carries the signalling/control information in its  packet header
7. More wastage of resources are common in circuit switching. Less wastage of resources are common in packet switching.
8. Message is received as in the order sent from the source, i.e. in circuit switching the entire message is received as it is as sent from a sender to receiver. Packets of a message are received out of order because of each packet travels a different path and finally assembled at the buffer of destination.
9. Circuit switching is more reliable. Packet switching is less reliable.
10. Circuit switching is done by using two common technologies, either Space Division Switching or Time-Division Switching. Packet Switching has two approaches Datagram Approach and Virtual Circuit Approach.
11. Circuit switching occurs in 3 phases –
i) Connection Establishment.
ii) Data Transfer.
iii) Connection Termination.
In Packet switching, data transfer takes place directly(without any phase creation).
12. In circuit switching, each data unit know the entire path address which is provided by the source at the time of release. In packet switching, each data unit just know the final destination address but intermediate path is decided by the routers.
13. Circuit Switching is implemented at Physical Layer. Packet Switching is implemented at Network Layer.
14. In Circuit switching, data is processed at source system only. In Packet switching, data is processed at all intermediate node including source system.
15.  Data transmission started after the circuit (static route) is established between the two end points for the duration of the transmission. Dynamic route is established for each packet which carries the routing information.
16. Delay between data units in circuit switching is uniform. Delay between data units in packet switching is not uniform.
17. Once the message is delivered to the receiver, the source informs the network about the completion of transmission and then all the switches released.  
They are mainly used with PSTN (Public Switched Telephone Network) connection line.
They are mainly used with ISDN  connection line.
19. Fixed/Static bandwidth allocation. Bandwidth is allocated dynamically.
20. Simple buffering. Better buffering. For this, system can be
operated at different bit rate as per need.
21. Message does not contain header, FCS etc. Packets has header, FCS etc along with data.
22. Costs more for hardware to create dedicated circuit. It is more economical as not needed dedicated circuit.
23. Once connection is established, communication is fast and almost error less. The packet needs to be re-transmitted every time when it gets lost/damaged before it is finally received by the receiver using this method.
24. Useful for delay sensitive applications Useful for bursty applications.

 240 total views,  1 views today


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.