Table of Contents
Bit-Byte Conversions
0,1 = bit
8 bit = 1 byte 1024 byte = 1 kilobyte (KB) 1024 KB = 1 megabyte (MB) 1024 MB = 1 gigabyte (GB) 1024 GB = 1 Terabyte (TB) |
1 mbps: 1 megabit/second
1 MBps: 1 Megabyte/second (???) 8 megabit/sec = 1 megabyte/sec |
Logic Gates
Command Line Shortcuts
Hold Window button & Press R key to open Run prompt. Then enter the shortcuts below::
- cmd = command prompt
- msinfo32 = system information
- SYSDM.CPL = system properties
- eventvwr = Event Viewer
- regedit = registry editor
- perfmon = performance monitor
- taskmgr = task manager
- DEVMGMT.MSC = device manager
- INETCPL.CPL = network connections
- IPCONFIG = IP Address Settings
- mstsc = remote connections
You can find more command line shortcuts here, if you need. But the above is what you need to know.
Windows Environment Variable: Sets the directory for the temporary files (that record the changes) of a running program i.e. Microsoft Word Document has the temp file that records changes saved to temp folder or desktop.
What is API?
Application Programming Interface (API) is interface for programming. Like Net-beans, Notpad ++ or Eclipse. The interface helps the programmer program by providing pre-made codes to work with to make the coding faster. An analogy of what API does is that instead of working with only your hands, you are given a toolbox to help you get your work done. That’s API

Multi-Tier Software Architecture
Multi-tier Architecture or n-tier architecture is a term used in Software Engineering that refers to the way software is divided. The software can be divided into presentation (what the person sees on the monitor display & interact with; GUI), Application processing and Data Management (communicating data from application to database).
The Three-tier architecture is the most common model used by Software Engineers, and another way to referenc the concept is by 1. Presentation, 2. Logic, and 3. data storage. Note that logic & data storage are the similar/same to application processing and Data management.
Multi-tier architecture is important because developers can use this model to make re-usable building blocks that saves time in coding applications. Another benefit of dividing the application into tiers or layers, is that the developers have the ability to change or add a specific layer; instead of re-coding the whole application. In other words, Multi-tier architecture saves the devs from re-inventing the wheel, so to speak.
Bug/Defect Life Cycle
The Defect Life Cycle is a cycle that a defect goes through during its existence. It starts when the defect is found and ends when the defect is closed and insured not to be reproduced in the software application. The Defect Life Cycle has several different stages that the bug goes through:
- New: When a defect is logged and posted for the first time.
- Assigned: After the Tester reports the bug, the Lead Tester approves the bug as genuine and the Lead assigns the bug to a developer in the developing team to fix the bug.
- Open: At this stage the dev starts to work on fixing the defect.
- Fixed: When a developer fixes the code that removes the bug. This corrected-bug code is passed on to the testing team to verify the fix. ↓
- Pending Retest: the corrected-bug is assigned to a tester to be retested
- Verified: The tester retests the corrected-bug code. If the tester approves the bug as fixed, the status of the bug becomes “verified”.
- Re-Open: If the bug if found (by the tester) to exists after it is ‘fixed’ by developer, then the status of the bug becomes “re-opened”.
- Closed: The tester find that the bug is indeed fixed, and the bug no longer exists in the software. So the status of the bug becomes “closed” and no longer needs to be worked on.
- Duplicate: If the same instance of a bug is found multiple time in a software. ie. First one is a defect, second one is the same type of defect, so there are two test cases which fail.
- Rejected: If the developer feels that the bug is not genuine, he rejects the bug.
- Deferred: The bug that is labeled ‘deferred’ is expected to be fixed in the next release. The reasons for changing the bug to this state include that the priority of the bug is low, lack of time to fix the bug before release, or that fixing the bug would change the software in a major way (thus being time consuming and expensive).
- Not a bug: This label is given when the reported defect does not change the functionality of the application. For example, if the client asks for a change in the look, or a field, or color of some text; then this is not a bug.