Difference between system software and application software?

Ans-  a system software is any computer software which manages and controls computer hardware so that application software can perform a task. Operating systems, such as Microsoft Windows, Mac OS X or Linux, are prominent examples of system software.System software contrasts with application software, which are programs that enable the end-user to perform specific, productive tasks, such as word processing or image manipulation. 

 
     Application programming is used to build application software which includes software like notepad, Word Pad, calculator, web browser, Microsoft excel and many more. Application software runs on top of system software. It interacts with system software which in turn interacts and makes physical hardware functional. 

   
System software is a software that deals directly with the architecture of the computer hardware. Operating system is a system software. Application software does NOT deal with the architecture of a computer.

 ___________________________________________

Difference Between Compiler and Interpreter?

Ans-  A Compiler and Interpreter both carry out the same purpose – convert a high level language (like C, Java) instructions into the binary form which is understandable by computer hardware. They are the software used to execute the high level programs and codes to perform various tasks. Specific compilers/interpreters are designed for different high level languages. However both compiler and interpreter have the same objective but they differ in the way they accomplish their task i.e. convert high level language into machine language. 

     The main differences between compiler and interpreter are listed below:

·         The interpreter takes one statement then translates it and executes it and then takes another statement. While the compiler translates the entire program in one go and then executes it.

·         Compiler generates the error report after the translation of the entire page while an interpreter will stop the translation after it gets the first error.

·         Compiler takes a larger amount of time in analyzing and processing the high level language code comparatively interpreter takes lesser time in the same process.

·         Besides the processing and analyzing time the overall execution time of a code is faster for compiler relative to the interpreter.

 __________________________________________

 

What are the difference between DDL, DML,DCL,TCL?

Ans- 

DDL

Data Definition Language (DDL) statements are used to define the database structure or schema. Some examples:

• CREATE - to create objects in the database
• ALTER - alters the structure of the database
• DROP - delete objects from the database
• TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
• COMMENT - add comments to the data dictionary
• RENAME - rename an object

DML

Data Manipulation Language (DML) statements are used for managing data within schema objects. Some examples:

• SELECT - retrieve data from the a database
• INSERT - insert data into a table
• UPDATE - updates existing data within a table
• DELETE - deletes all records from a table, the space for the records remain
• MERGE - UPSERT operation (insert or update)
• CALL - call a PL/SQL or Java subprogram
• EXPLAIN PLAN - explain access path to data
• LOCK TABLE - control concurrency

DCL

Data Control Language (DCL) statements. Some examples:

• GRANT - gives user's access privileges to database
• REVOKE - withdraw access privileges given with the GRANT command

TCL

Transaction Control (TCL) statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions.

• COMMIT - save work done
• SAVEPOINT - identify a point in a transaction to which you can later roll back
• ROLLBACK - restore database to original since the last COMMIT
• SET TRANSACTION - Change transaction options like isolation level and what rollback segment to use
• TCL is abbreviation of Transactional Control Language. It is used to manage different transactions occurring within a database.
  Examples: COMMIT, ROLLBACK statements
   

SQL statements are often divided into three categories:
DML (Data Manipulation Language). These SQL statements are used to retrieve and manipulate data. This category encompasses the most fundamental commands including DELETE, INSERT, SELECT, and UPDATE. DML SQL statements have only minor differences between SQL variations. DML SQL commands include the following:

• DELETE to remove rows.
• INSERT to add a row.
• SELECT to retrieve row.
• UPDATE to change data in specified columns.
• DML is abbreviation of Data Manipulation Language. It is used to retrieve, store, modify, delete, insert and update data in database.
  Examples: SELECT, UPDATE, INSERT statements
   

DDL (Data Definition Language). These SQL statements define the structure of a database, including rows, columns, tables, indexes, and database specifics such as file locations. DDL SQL statements are more part of the DBMS and have large differences between the SQL variations. DML SQL commands include the following:

• CREATE to make a new database, table, index, or stored query.
• DROP to destroy an existing database, table, index, or view.
• DBCC (Database Console Commands) statements check the physical and logical consistency of a database.
• DDL is abbreviation of Data Definition Language. It is used to create and modify the structure of database objects in database.
  Examples: CREATE, ALTER, DROP statements
   

DCL (Data Control Language). These SQL statements control the security and permissions of the objects or parts of the database(s). DCL SQL statements are also more part of the DBMS and have large differences between the SQL variations. DML SQL commands include the following:

• GRANT to allow specified users to perform specified tasks.
• DENY to disallow specified users from performing specified tasks.
• REVOKE to cancel previously granted or denied permissions.
• DCL is abbreviation of Data Control Language. It is used to create roles, permissions, and referential integrity as well it is used to control access to database by securing it.
  Examples: GRANT, REVOKE statements
  
  
  
  What is difference between MICR , OCR and OMR..?
  
  
  MICR - Magnetic Ink Character Recognition is a character recognition technology adopted mainly by the banking industry to facilitate the processing of cheques. And the characters are of unique fonts.
  
  MICR characters are printed with a magnetic ink or toner, usually containing iron oxide
  
  OCR- Optical Character Recognition(Can recognize Characters from hard text ). Technique to recognize characters. Characters do not need to be in unique font. Characters may be hand written or type written
  
  OMR- Optical Mark Recognition(Only can recognize mark for example a filled circle but cant recognize any character) 
  
  
  

  MICR vs OCR

  MICR and OCR are technologies increasingly being used in businesses these days. While OCR is Optical Character recognition, MICR stands for Magnetic Ink Character recognition. Though these techniques have similarities there are difference and specific uses that will be discussed in this article to help people differentiate between these two technologies.

  MICR

  MICR or My-ker as it is popularly known as is used in the banking industry in many countries of the world to ensure authenticity of a check or a demand draft using simple and inexpensive machines. The bottom line on these MICR checks is printed using a special magnetic ink. It is this ink that allows the information written on the check to be authenticated through machines. This facilitates processing of a huge number of checks in a single day which is otherwise very tedious. MICR typeface has only 14 characters in it including 0-9 and four special symbols that indicate Transit, Amount, on/us, and dash. As MICR is limited to only 14 characters, it is not possible to print an entire check using this special magnetic ink.

  OCR

  OCR allows a machine to automatically recognize characters using an optical mechanism. Most of the OCR systems recognize numbers only and very few of them can understand the full alphanumeric range. OCR is used to enter data automatically into a computer for processing. OCR was initially used to decipher petroleum credit card sales drafts. This application allows recognition of the purchaser with the help of the credit card account number. Any standard form or document with repetitive variable data is easily read using OCR technology.

  Summary

  • While MICR is mainly limited to finance industry, particularly banks to prevent frauds through use of counterfeit checks and demand drafts, OCR has much wider application and is used in many industries.

  • OCR is today being used in schools, government institutions and other businesses.