The term "Boolean," often encountered when doing searches on the Web (and sometimes spelled "boolean"), refers to a system of logical thought developed by the English mathematician and computer pioneer, George Boole (1815-64). In Boolean searching, an "and" operator between two words or other values (for example, "pear AND apple") means one is searching for documents containing both of the words or values, not just one of them. An "or" operator between two words or other values (for example, "pear OR apple") means one is searching for documents containing either of the words.

In computer operation with binary values, Boolean logic can be used to describe electromagnetically charged memory locations or circuit states that are either charged (1 or true) or not charged (0 or false). The computer can use an AND gate or an OR gate operation to obtain a result that can be used for further processing.
http://searchcio-midmarket.t echtarget.com/sDefinition/0,,s id183_gci211695,00.html

Answered by Nishu's , an ibibo Master, at 10:59 PM on October 24, 2008

Boolean operators are used in programming. It would be hard for me to explain exactly how they are used in programming without giving you a programming course, but I can tell you basically what they do. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So:

* (true AND true) makes true
* (true AND false) makes false
* (false AND true) makes false
* (false AND false) makes false

* (true OR true) makes true
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

* (NOT true) make false
* (NOT false) makes true

XOR is the same as OR except that it only allows one or the other to be true; not both:

* '''(true XOR true) makes false'''
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

Boolean operators can be mixed together like this:

NOT (true XOR (false AND true)) makes false

In programming, you often use symbols to represent these instead of writing out the words. OR is ||, not is !, and AND is &&.

-DJ Craig

Answered by Sandeep , an ibibo Citizen, at 7:20 PM on October 24, 2008

The basic logical operators are:

Negation (not) (¬ or ~)
Conjunction (and) (\wedge or &)
Disjunction (or) (\vee)
Material implication (if...then) (\rightarrow, \Rightarrow or \supset)
Biconditional (if and only if) (xnor) (\leftrightarrow, \equiv, or = )



Some others are:

Exclusive disjunction (xor) (\not\leftrightarrow)
Joint denial (nor) (↓)
Alternative denial (nand) (↑)
Material nonimplication
Converse nonimplication
Converse implication
Tautology
Contradiction

Answered by ani , an ibibo Advisor, at 6:55 PM on October 24, 2008

Boolean operators are used in programming. It would be hard for me to explain exactly how they are used in programming without giving you a programming course, but I can tell you basically what they do. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So:

* (true AND true) makes true
* (true AND false) makes false
* (false AND true) makes false
* (false AND false) makes false

* (true OR true) makes true
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

* (NOT true) make false
* (NOT false) makes true

XOR is the same as OR except that it only allows one or the other to be true; not both:

* '''(true XOR true) makes false'''
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

Boolean operators can be mixed together like this:

NOT (true XOR (false AND true)) makes false

In programming, you often use symbols to represent these instead of writing out the words. OR is ||, not is !, and AND is &&.

Answered by Om Prakash , an ibibo Master, at 6:37 PM on October 24, 2008

Boolean operators are used in programming. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So:

* (true AND true) makes true
* (true AND false) makes false
* (false AND true) makes false
* (false AND false) makes false

* (true OR true) makes true
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

* (NOT true) make false
* (NOT false) makes true

XOR is the same as OR except that it only allows one or the other to be true; not both:

* '''(true XOR true) makes false'''
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

Boolean operators can be mixed together like this:

NOT (true XOR (false AND true)) makes false

In programming, you often use symbols to represent these instead of writing out the words. OR is ||, not is !, and AND is &&.

They are mainly used in search engines.

Answered by Kamlesh B , an ibibo Specialist, at 6:26 PM on October 24, 2008

well,They are often used by search engines.

If you put in "Bob" AND "Smith" you would get results that have both Bob and Smith in them (say 150 results).

If you put in "Bob" OR "Smith" you would get any result with Bob or Smith (say 3000 results).

If you put in "Bob" NOT "Smith" you would get Bob Jones, but not Bob Smith.

Not all search engines use these. And some use other terms for them.

Answered by Debashis , an ibibo Master, at 5:45 PM on October 24, 2008

Boolean operators can be used in the standard Search mode. Boolean operators are little words that make a big difference in your search. They are used to create logical statements for refining searches. Use the following Boolean operators to create rules for a search to follow:

AND specifies that you want each and every search word grouped by an AND to appear in the results. Example: German AND shepherd would return only results that contain both "German" and "shepherd."

OR yields search results that contain any one or all of the words in your multiple-word query. Example: Yugoslavia OR Bosnia would return results that contain either "Yugoslavia" or "Bosnia," or both terms.

NOT (or the minus sign [-]) excludes words from your search results. Example: Washington NOT George would return results that contain "Washington" but do not contain "George."

[+] (plus sign) yields only search results that include the word to the right of the plus sign. Example: India + Buddha would return results that contain "Buddha" and would give priority to results that also contain "India."
Use parentheses to group Boolean operators.

Use parentheses to separate or group Boolean operations into a larger formula:

Example: Cherokee AND (language OR alphabet) NOT sequoyah would return results that combine "Cherokee" with either "language" or "alphabet," but would exclude any results that contain "sequoyah."

Example: (Yugoslavia OR Bosnia) AND "war tribunal" would return results that contain the words "war tribunal" in order, and of those results, only those that also contain either the word "Yugoslavia" or the word "Bosnia."

Answered by Alok , an ibibo Master, at 5:42 PM on October 24, 2008

well, Boolean operators are used in programming. It would be hard for me to explain exactly how they are used in programming without giving you a programming course, but I can tell you basically what they do. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So:

* (true AND true) makes true
* (true AND false) makes false
* (false AND true) makes false
* (false AND false) makes false

* (true OR true) makes true
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

* (NOT true) make false
* (NOT false) makes true

XOR is the same as OR except that it only allows one or the other to be true; not both:

* '''(true XOR true) makes false'''
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false
source site: http://wiki.answers.com/Q/What_are_ Boolean_operators_and_how_are_they_ used

Answered by Santosh Kuma , an ibibo Master, at 5:39 PM on October 24, 2008

Boolean operators are used in programming. It would be hard for me to explain exactly how they are used in programming without giving you a programming course, but I can tell you basically what they do. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So:

* (true AND true) makes true
* (true AND false) makes false
* (false AND true) makes false
* (false AND false) makes false

* (true OR true) makes true
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

* (NOT true) make false
* (NOT false) makes true

XOR is the same as OR except that it only allows one or the other to be true; not both:

* '''(true XOR true) makes false'''
* (true OR false) makes true
* (false OR true) makes true
* (false OR false) makes false

Boolean operators can be mixed together like this:

NOT (true XOR (false AND true)) makes false

In programming, you often use symbols to represent these instead of writing out the words. OR is ||, not is !, and AND is &&.

-DJ Craig

Answer

They are often used by search engines.

If you put in "Bob" AND "Smith" you would get results that have both Bob and Smith in them (say 150 results).

If you put in "Bob" OR "Smith" you would get any result with Bob or Smith (say 3000 results).

If you put in "Bob" NOT "Smith" you would get Bob Jones, but not Bob Smith.

Not all search engines use these. And some use other terms for them.

Answered by Ashish Yadav , an ibibo Wizard, at 5:37 PM on October 24, 2008