What are functional and non-functional requirements?

Hello 👋

This is my first post on dev.to. I am starting to write while improving my english and tech skills. To start, I will write about requirements and their two main types: functional and non-functional requirements.

Requirements are an essential part of developing a new software. They need to be clearly defined on the road that leads to a successful project. There is a lot of requirement types. Here I will focus in two types I think that are the main ones.

Functional Requirements
Functional Requirements are products features or functions that must be implemented to enable users to accomplish their tasks. These requirements must be clear to stakeholders in order to avoid future problems in the project. They define all the things that the system must do.
Here, some examples of functional requirements:

• Business rules that must be met.
• External interfaces of the system.
• Steps that the system must take in authentication.
• The reporting requirements.

Non-Functional Requirements
These are the requirements that describe how the system works and they aren`t related with the system functionalities. Some examples are:

• Speed: How fast the system works, or some module should work.
• Capacity: What are the system limits.
• Usability: How easy the system is for its users. Is the things clearly enough? Could the user use the system without any problem?
• Reliability: How dependable the system is.

These are only some examples about non-functional requirements. There are a lot of other types.

I hope that you like the post. It`s my first try in english, so sorry about possible spelling errors, I will be better.

Thank you!