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Bugs are an annoying part of life whether they’re the kind that land on you when you’re enjoying a barbecue or the kind that slow down your latest software release. The latter can be minimized, but will never be fully eradicated throughout the stages of building a product or feature. Testing and bug bashes follow inception in order to clear the field. Some land even earlier in the development process.
There are mixed ideas on where the term comes from, but one of the most popular involves programmer Grace Murray Hopper and her team at Harvard. It was the mid-1940s, and the university’s Mark II electromechanical computer was acting up. After opening it up, they found an actual moth inside. And the rest is history. There are also ties to Thomas Jefferson. He once wrote to a friend in 1878 referring to a mechanical malfunction in his telegraph system as a “bug”.
Regardless of their origin, knowing what you’re dealing with can make bugs easier to discover and faster to deal with. Much like mosquitos and ladybugs, software bugs can be categorized. Take a look at some of the most common types you’ll see as a developer.
Logical (Logic) Bugs
Logical bugs mess up the intended workflow and can lead to the software giving the wrong output, hanging, or crashing. It’s usually due to coding errors. A common one here is the infinite loop. A program will repeat a sequence indefinitely until it crashes or someone intervenes externally by closing a browser window or shutting the power off.
You also might see issues resulting from dividing two numbers vs. adding them, leading to unexpected output. Or assigning a value to the wrong variable.

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Functional Bugs
Unsurprisingly, functional bugs affect functionality of a feature or the software as a whole. When things don’t work like they’re supposed to, users are going to drop off fast, so these tend to be pretty high priority. This might be a login button that doesn’t allow you to log in or when clicking save doesn’t work and leads to loss of data.
Basically, anything that isn’t working as intended falls under this category. Sometimes, after further investigation, the root cause can be reclassified under a different category.
Usability Bugs
While they sound similar to functional bugs, usability bugs can be thought of with a slightly different perspective. The former determines if your software works like it’s supposed to. The latter determinds whether or not the end user can reach those functions and use the product like it was intended. Consider these urgent. If a user can’t use the product, if it’s not working to its fullest extent or it’s completely unusable, you’ll lose customers, money and reputation. One usability bug could be an ineffective layout.

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System-Level Integration Bugs
When you combine two pieces of code done by different developers, sometimes, despite a requirements list for people to follow, they don’t interact appropriately. It’s usually from incompatibility or inconsistencies between components. These get a bit trickier, as they involve more than one piece of software. With larger amounts of code to sort through, these bugs are harder to track and resolve, and they take more time to replicate. One example of this is memory overflow issues.
Performance Bugs
As the name implies, performance bugs affect the performance of your software: stability, speed, resource consumption, etc. During performance testing, when the product is loading or responding slowly, your bugs will likely fall into this category.

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Out of Bound Bugs
Out of bounds bugs can occur when a user interacts with software UI in a way that is unexpected. You might see this when they enter an input value of an undefined data type. It might also be as simple as using a vastly higher or lower value than expected. Functional testing should turn out most of these.
Compatibility Errors
Compatibility errors come into play when your product doesn’t work with certain hardware or common operating systems. While it might not be an immediate consideration in early-stage startups, making your app work with what your users have at home goes a long way in increasing your customer base. They’re unlikely to change hardware or OS and instead are likely to find different software to meet their needs.
Unit-Level Bugs
These are some of the most common–and easiest to fix–of the bugs. With unit-level testing, done after the major parts are complete, developers can check small parts of code at a time. With less to look over, errors are more readily found and tend to not be very damaging. One example might be checking through a form page that all the input fields are working as intended. If not, that would be considered unit-level.

Security Bugs
Security is a big deal. Period. Security bugs are risky for users and should be high priority when being fixed. Not only is a user’s data at risk, but so is the reputation of your company. Security bugs might not affect functionality but can compromise a system as a whole and make it vulnerable to cyber attacks. Examples include logical and encryption errors and XSS vulnerabilities. Check early and often for these to avoid a disaster.
Syntax Errors
Syntax errors are another of the most common bugs. Inaccurate or missing characters from the source code will affect compiling. Even a single missing bracket can cause issues. These minimalistic human errors can usually be pointed out using compiling programs, so they can be easily fixed.
As with most things, there is a priority ranking system to determine what you should tackle first. It starts with low severity bugs, issues that cause little to no damage to the function of the software. They’re more blips in the user interface. On the opposite end of the spectrum are critical bugs, issues that cause the most damage to the functionality of the software and halt progress until addressed.
One of the quickest ways to facilitate fixing bugs is by using Dashcam. You’ll catch them in action with passive screen recording and can easily attach the footage to a bug report to provide full context to the person on repair duty. Find those bugs before your customers do, and you’ll save a headache down the line.