User interface design is how humans interact with the computer, the goal is to make the life of the users as simple as possible.

The design is the process that is needed by creating webpages,  myself applications, by building assessment and by creating any interactive device.

There’s a lot that goes into creating a beautiful (and usable) interface. It’s a constant balance between creating something that looks amazing and still makes sense to your users.

Principles :

Clarity

Conserve attention at all costs

Keep users in control

Direct manipulation is best

Keep secondary actions secondary

Provide a natural next step

Consistency matters

Appearance follows behavior

Strong visual hierarchies work best

Smart organization reduces cognitive load

Highlight, don’t determine, with color

Progressive disclosure

Great design is invisible

Build on other design disciplines

Software maintenance is the activities perfomed to keep software operational. Those activities are code changes, configuration changes and environment changes

Code changes involves changes to the software of the source code of the software, this is done by developers. This is needed in order to debug de code.

Configuration changes are parameters that control the behavior of the software, this can be set of chains after the software has been built. This is done by tech support or operator.

Environment Changes is the modification of a softwareproduct after delivery to correct faults, to improve performance or other attributes. A common perception of maintenance is that it merely involves fixing defects.

Everyone have navigated on a website, in the menu of an application or in the menu of the video game like the settings, and had positive thoughts about it, for example: “it very easy to use this app”, “I found really fast the setting I was looking for”, “The use of this app almost feels like something natural”. But there are also negative that frustrate us because we can’t do what we want with the application, for example: “I don’t understand how to use this app”, “I got lost in the navigation menu”, “I can’t find the setting I changed early”, etc.

The reaction or the experience of the user when using software doesn’t only depend on the functionality and the aesthetically design, what more influences the user to feel comfortable or not is the user interface.

User Interface (UI) Design focuses on anticipating what users might need to do and ensuring that the interface has elements that are easy to access, understand, and use to facilitate those actions.

                                                                        From usability

This means that user interface design is about thinking like a common user instead of an experience programmer that already knows what the software does. It can also be interpreted as molding the functionality of the software so it could be used more “naturally”, in other words, that you can use the software like if it where something of common sense.

There many elements, principles and other concepts in user interface design that explaining all of them will make this post very huge, so I will share this page to find more info about it.

References:

https://www.usability.gov/what-and-why/user-interface-design.html

http://bokardo.com/principles-of-user-interface-design/

Maintenance is a well-known concept, the general idea is to prevent things to stop doing what is supposed to do; this can be applied to everything, for example, we usually have the car to have maintenance so we can prevent future problems that will be more expensive than the maintenance.

In software there is no difference, every program needs maintenance to prevent future problems, even if software is not a physical thing, is also a product that has a functionality, and because of that, is vulnerable to suffer malfunction with the time.

Software maintenance is defined as the process of modifying a software system or component after delivery to correct faults, improve performance or other attributes, or adapt to a changed environment.

            From here.

As the previous quote suggest, maintenance corrects faults, improve performance, adapt and prevents problems; this means that there four types of maintenance: the corrective, the adaptive, the perfective and the preventive.

The corrective seeks for malfunctions and problems in the system, then it modifies it to solve problems and bugs; the adaptive applies modification to keep the product up to date to the ever changing world of technology and business environment; the perfective is to improve performance and to keep the software usable over a long period of time, as well as adding more functional requirements and new features; and the preventive aims to attend insignificant problems that may cause serious problems in the future.

Software maintenance is the last step of the software life-cycle; from here you may be wondering why is a cycle? why the gathering is required again? This is because in maintenance you are looking for new problems and new requirements that then, you will have to design,