A is required to fulfill the standard of B (that is how requirement comes from). Some needs coming from the users, the customers.

The word "requirements" can indicate prerequisites to achieving something, so that is why it is used in this case. In casual dialogue you can say that you have a need for a list of A, B, and C objects. For example, "I have a need for chocolate and ice cream to survive." However, in this context, it is more formal and technical. Therefore, technical dialogue would not use the word "a need" or "needs" as a synonym for "a list of things that must be completed before reaching a particular goal."

Requirements are more like items on a checklist. In this example the requirements are needed, but 'needs' is implied. If we used 'need' this would read as 'However, certain requirements are needed', which is correct but sounds verbose.

Hi, requirements are a type of need, but the word "requirement" denotes something more formal and structured than just a need. If the question at hand has anything to do with formal documents or processes (patent law, applying for a school, job interview, legal issues, citizenship, contracts, etc), then almost certainly the preferred noun will be "requirement." Here are some examples of how these concepts are related as verbs. (On both sides of the equal sign, the sentences mean the same exact thing.) I am *required* by law to register my car. = I am *obligated* by law to register my car. So, I *need* to register my car. = So, I *must* register my car. I *need* to because I am *required* to do it by law. = I *must* do it because I am *required* to do it by law. It is a *requirement,* so I *need* to do it. = It is a *requirement,* so I *must* do it. Hope that helps a little!

As Pao said I do not think this is a good fill-in question however you may see the real meaning of "requirement or require" through this practice.