Computer Science & IT Professional Knowledge

The word netizen is used to refer to the number of people in a country who have access to internet facilities. Thus, it shows the computer penetration in a country.

CAB stands for compressed application binary. It is also called cabinet. It stores smaller files that can be extracted without affecting other files.

INS key is used to toggle insert and overwrite mode.

Windows identify a file type by its extension and then decides which program will open that file. A compressed file generally has an extension “.zip” and is opened by WinZip/IZArc.

It is a worldwide character standard. It provides 2 bytes, i.e. 16 bits for each symbol.

Yacc is an acronym for “Yet another compiler compiler”. It is a parser generator program in UNIX operating system. Its loading schemes are: Absolute loader, Relocating loader, Dynamic loading and Dynamic linking.

Semaphore is an integer variable that is accessed through two variables, wait and signal. The initial value of semaphore should be 1 for granting only one process among many processes to enter their critical section. It helps in synchronisation of processes.

String is a collection of characters. To find the last occurrence of a given character in a string, the keyword “strrchr” is used.

B+ tree is a type of tree which represents sorted data for efficient insertion, retrieval and removal of records. It stores all records at leaf level and all keys at interior nodes.

Deadlock is a condition in which process execution continues without coming to an end and prevents other processes from starting. It occurs when four conditions hold simultaneously - mutual exclusion, hold and wait, no preemption and circular wait.

PICO stands for pine composer. It is an easy-to-use text editor for UNIX and UNIX-based system.

Auxiliary carry (AC) is one of the five status flags of 8085 microprocessor. It stores one if there is a carry from bit 3 to bit 4, counted from right.

Primary key is chosen by a designer to uniquely identify rows in the table. It is always not null and unique. A null value can be used to represent an unknown data.

An E-R diagram is a method to pictorially represent business findings. It has four types of cardinality of relationships - One to one, one to many, many to one and many to many.

Normalisation is a refinement technique. It is used to remove anomalies in insert, update and delete operations. It is a bottom-up approach and is based on mathematical foundations.

Data control line (DCL) is a type of SQL statement. It is used to provide control over the data in a database and to define the end of a transaction.

Domain consultant is a role in software projects. He is an expert with knowledge about the system of which the software is a part. He analyses the interfacing between entities of domain and software to be developed.

Data warehousing is a method of collection and storage of data so as to facilitate efficient data analysis and decision making.

Waterfall method is a software model used for software development. It consists of many phases of software development. Build phase includes translation of program specifications into machine-readable form. Integration testing is done in this phase.

Scheduling process permits one process to utilise the CPU, while another is waiting for I/O, making full utilisation of generally lost CPU cycles.

In batch operating system, the program and data are gathered together in batches and then processing starts. It does not utilise the CPU efficiently as the CPU is often idle. It is because of speed difference between CPU and I/O devices.

The Banker's algorithm is a deadlock avoidance algorithm created by Edsger Dijkstra that tests for safety of all assets and after that, makes an "s-state" check to test for possible deadlock conditions.

The attempt to find a password by sequential trial of all possible combinations until the right combinations are found is called brute-force attack.

Spoofing is the act of impersonating to gain unauthorised access to a user’s private information by creating IP packets having forged IP source addresses.

Artifact-based authentication system refers to the use of machine readable badges which help in authentication of the user. Electronic smart cards also contain a magnetic strip which is read by the device to authentic its use.

Real-time operating system collects data from the surroundings and processes it to give instant results. In it, time interval required to process and respond to input is negligible compared to online processing.

Trojan horse is a malware. It would show that it is performing a desirable function, but contains a hidden code that is intended to allow unauthorised modification or even deletion of data.

Network layer is the third layer of the OSI model. It provides communication between different networks. It is responsible for formatting of data, addressing and routing.

Sparse array is an array which assigns a default value to all its element. It may be a constant or null.

Secure sockets layer (SSL) is a security method. It creates an encrypted link between server and client.

ISO/IEC 12207 is an international standard which is used for providing guidelines and framework for software life cycle processes.

In UNIX, the command “pgm>>file” is used for appending the output of pgm to file.

Hyper text transfer protocol is used to transfer information from worldwide web to browsers.

Spreadsheet is an interactive program. It facilitates storage, arrangement and analysis of data. It allows user to alter any number and check the result of that alteration immediately.

In a spreadsheet, Book 1 shows the process of naming and numbering of name box in each work session.

The difference between memory and storage is that memory is temporary and storage is permanent.

The word length of a 32-bit microprocessor is 4 Bytes.

RDBMS is based on relational model. It arranges the data in tables by finding relations between them.

Textbook tool enables the addition of text to a slide without using the standard place holders.

Local variables are C program variables and hold scope inside a function only. Global variables hold scope for an entire program.

The automatic shifting of cursor to the next line in MS-Word on reaching the right edge of the screen is called word wrap.

MIPS stands for million instructions per second. It measures the performance of a CPU in terms of processed data.

Tunneling allows a user to transfer data to a private network from a public network, when both have different network protocols.

Dumb terminal is an output device. It stores the data received from the CPU, but does not process it.

 The minimum length of an ethernet frame is 64 bytes and the maximum length is 1518 bytes.

 IANA stands for internet assigned number authority. It is a department of ICANN and supervises the allocation of IP addresses, port addresses and other numerical standards.

 Symbols are used to show text/graphics that cannot be shown in sufficient detail for the whole document.

MIDI stands for musical instrument digital interface. It allows exchange of information between musical synthesisers and computer.

Page addressing is the addressing mode in which memory is partitioned in pages and each address is held in page table.

Bootstrap protocol is an internet protocol. When a network device connects to a configuration server, an IP address is automatically assigned to the device.

E-tailware is a software used by websites which sell products online. It is used to provide support services, ranging from creating catalogue of products to credit checking of buyers and customers.