Types of Bugs and Errors in Software Testing

Software testing is an ongoing process in agile project development. Software engineering defects are essential if you wish to work in QA testing. It is important to be able to identify the causes, consequences, and characteristics of errors in the SDLC process. You must be aware of the SDLC process as the same problem may occur in different build versions.

There are many kinds of software in the market. Even if your not a programmer, it is helpful to be familiar with the types of software and bugs. This is especially important if your business or organization uses any type of computer system application. This article will help you classify the most common bugs that every tester should know.

What’s Software Testing?

Testing refers to the identification of specific problems or issues during software development. A tester is someone who tests functionality and provides information to developers.

Within a specified time frame, a tester team can identify application bugs. The testing team then provides the list of bugs to the system developers. The product errors are then fixed before it can be used by the end user.

What’s a Software Bug?

Any known or undiscovered error that occurs in the SDLC lifecycle is a bug. According to Wikipedia, a software bug is any error, flaw, or fault in a computer system or program that causes it produce an unexpected or incorrect result or behaves in an unintended manner.

Types of bugs in Software Testing

Software bugs can be classified into three types, regardless of their software type: Nature, Priority and Severity. Software bugs are classified based on their impact on user experience and nature.

Software bugs by Nature

Software bugs can have different types that affect the software’s overall functionality. Although there are many of these bugs, they may not be something you see often. These are the most common bugs in software that you will encounter during your career in software development.

Performance Problems

Poor performance is not something that any user would want to use. Performance bugs are software bugs that cause slow loading speeds, instability, high response times, or higher resource consumption. If you notice a slower loading time than normal or an increase in response times, this is a sign that there is a bug in the software. The developer can diagnose a performance bug if such a sign is detected. Every such bug in the software is detected during the performance testing phase.

Security Problems

Security is the number one concern for users of software. Poor security software will not only expose the user’s data but also harm the organization’s image, which could take many years to recover. Security bugs are among the most serious bugs. Security bugs can make software more vulnerable to cyber threats, even though it is obvious. These attacks can sometimes go unnoticed by the software company, but in certain cases they could result in financial loss for users, particularly small- and medium-sized businesses. XSS vulnerabilities and logical errors as well as encryption bugs are the most common security flaws found in software. To minimize cyber-attacks, developers pay special attention to checking code for any security bugs.

Unit Level Bugs

Software development is not prone to unit-level bugs. They are quite common and don’t cause too much damage. Unit-level bugs include basic logic bugs and calculation errors. Together with the agile team, the testing team tests a portion of the code. This testing method is preferable because it ensures that all code works as it should. Because the code is small, it’s possible for the team to encounter unit-level bugs while testing. These can be easily fixed.

Functional Bugs

Software is only as good as its features. The number of users of software will drop dramatically if it is not functional. Functional bugs are when one feature or all of the software stops working properly because of an error. The severity of these bugs will depend on what feature they are affecting. A clickable button that does not respond is not necessarily a bug. The testing team conducts functional testing to find any software bugs that could cause functionality problems. Once a bug is identified, the team determines its severity and classification.

Usability Problems

A usability bug, or defect, is one of the most serious bugs in software. It can make the software unusable or prevent it from reaching its full potential. This bug can be found in software testing as the inability to log into the user account, or inefficient layouts of the software. This bug or defect can make the software difficult to use. While testing the code for such bugs, developers and engineers must ensure that the requirements are met.

Syntax Errors

Syntax errors are one of the most common software bugs. They prevent the application from being compiled correctly. This bug is caused by an error or missing character in the source code. The compiling process will be affected. This could be caused by a small error, such as a missing bracket. This bug will be discovered by the testing or development team during compilation. They will then analyze the source code to correct the incorrect characters.

Compatibility Errors

A compatibility error is when software or applications are not compatible with an operating system or hardware. Compatibility errors are not common as they might not be detected in initial testing. To ensure that the software they create is compatible with different operating systems and hardware, developers should conduct compatibility testing.

Logic bugs

One of the most common bugs in software code is logic errors. These errors cause the software to give incorrect output, crash, or fail. These bugs can be caused by coding errors, which may cause the software to get stuck in an endless loading loop. The only thing that could break the loading loop is an external interruption or software crash.

Priority-Based Software Bugs

Priority-based software bugs is the main category. These bugs are classified according to their impact on the business. The developers will then analyze each bug to determine its severity and priority. The timeline for each bug is then given. This will minimize its impact on the user. These are the types of software bugs that are priority-based.

Low-priority defects

They are not likely to have a significant impact on the functionality of the application. They are more about software aesthetics. A low-priority defect could include an issue with text or spelling. Software testing will proceed to the exit criteria, even if low-priority defect are not corrected. However, they must be fixed before the final release.

Medium-priority defects

Medium-priority bugs are similar to low-priority ones, but they can have a significant impact on the software and should be addressed in any future or subsequent releases. These defects might not have the same effect on every user. It may also vary depending on the particular device and configuration.

High-priority defects

The exit criteria for high-priority bugs are different from the other two. They can’t be removed until the problem is fixed. Using certain software features may be impossible due to every bug in this category. It is important to fix bugs in this category before you move on with software development or testing.

Urgent Defects

This category covers all bugs that must be addressed immediately, as the name implies. Urgent defects can have a significant impact on brand image and negatively affect user experience. These bugs can be fixed within 24 hours of being reported.

Software bugs by severity

The bug’s technical impact on the software can be divided into four groups.

Low Severity Viruses

As the primary goal of low severity bugs, they do not cause significant damage to the software’s functionality. The font used in the text may not be the same font as the one used. These bugs are easily fixed and not something to be concerned about.

Severity bugs of medium severity

A bug of moderate severity is any bug that has the potential to affect the software’s functionality. These bugs can cause the software to behave differently than it should. They aren’t necessarily major, but they need to be fixed in order to improve the user experience.

Severity High Bugs

Software functionality can be affected by severe bugs. They cause it to behave differently than it was intended. These bugs can be very destructive to the software and sometimes render the entire program unusable.

Critical Bugs

Critical bugs are bugs that could cause serious problems and can have a significant impact on the overall functionality of the software. Critical bugs are the most dangerous bugs because they prevent further testing of the software until such bugs are found.

How do you find software bugs that are under-reported?

To ensure the software works properly, it is important to find a software bug. The question is, however, how do you find software bugs? Here are some ways developers can find software bugs.

  1. Test Cases:
    A developer’s first tool for identifying bugs in software is the test case. Before they start testing, every developer needs to prepare great test cases. Functional test cases are also important as these will allow them to analyze the risk and predict how the application will perform under different conditions.
  2. Device Test:
    Sometimes developers just test their code on a virtual machine and leave behind real devices. While this approach can work in some cases, it is not practical for large-scale software. Developers should extend their testing reach to test the software on real devices. This will help developers understand how the software works on different configurations and will also help you to determine its compatibility.
  3. Use bug tracking tools:
    The easiest way to find bugs in software is with bug tracking tools. These tools make software testing much easier by allowing you to track, report, and assign bugs. This task can be accomplished with several tools such as SpiraTeam and Userback. ClickUp makes software testing simple.


Practically, it is impossible to eradicate all bugs from software. Some bugs are inevitable with every update or new version of software. Instead of trying to find every bug and fix them, developers and testers assess the severity of each bug and decide if fixing it is worth the effort. To find complicated bugs in software, ThinkSys Inc conducts software testing. Our software testers develop a strategy to help prioritize bugs that will improve the software with each update. This is done to detect errors early so that software can be released quickly and without any errors.

Comments are closed.