Definition

Bug is a hardware or software problem that leads to errors or problems on the equipment and program, so it can not function normally.

The term 'bug' was first used by a computer scientist, Grace Hopper when he was firstly handling a problem where there was an insect that stuck in an electromechanical computer, where it was found that there was an insect that was stuck in it. As a result, it causes a new problem at the computer.

Frequently Comes Up Bug

1. Compilation Error

If there is a compilation error while running the application, it indicates that there is a problem with the application. It happens as a lack of developer's accuracy at the component while developing the application, such as variable, functions, etc.

2. Runtime Errors

Runtime error is an operation which can be made but unable to produce anything. A simple example is the integers that are divided by 0. It shows nothing when it is running. However, the bug will appear when it comes to the runtime.

3. Logic Errors

A Logic error is a very common mistake. This problem happens since the developer does not fully understand how the features should be implemented.

4. API bug

A bug which has broken the API and it causes an action to be unable to respond properly.

5. Application Crash

This type of bug is often encountered in cellular applications, which causes the application to stop working properly.

6. GUI Related bug

A bug that happens because there are interface design errors, application form, and page layouts on various layer sizes.

7. Database bug

A bug that happens in the database if it is not updated and well managed.

8. System related bug

Every program which is not compatible with the operating system, hardware, or environment can cause problems.

9. Software service pack

If a new update is available in the system and the application is not compatible with the new update, it can cause problems.

The types of Bug

Arithmetic

It is a bug that occurs due to errors in arithmetic operations. Examples: 

• Division by zero
• Unstable arithmetic algorithm
• Overflow or underflow arithmetic

Logic

is a bug that occurs when there is a problem with the logic to process an instruction. Examples: 

• Unlimited Loop (iteration)
• Error off by one

Syntax

It is a bug that occurs due to errors in the use of operators used in completing a command. Examples:

• X = 5 means x is 5
• X = = 5 means checking whether the value in the variable x is 5 or not.

Resource

It is a bug that occurs due to errors at resources used to solve a problem. Examples:

• Using uninitialized variables
• Using inappropriate data types
• Access offense
• Excessive recursion causes stack overflow

Multi-Threading

It occurs due to an error in running the commands separately. Examples: 

• Deadlock: It happens when task B can not be executed before task A is completed.
• Race condition: It happens when the computer does not perform the task order as the programmer wants.

Interfacing

It is a bug that occurs due to errors in the interface. Examples: 

• The incorrect API usage
• The incorrect protocol implementation
• Incompatible system