GIVE ANSWERS - English

@ the most elementary level:
1. Usability: the state of being "usable", applied to anything that one might "use" to perform X task, and the fact that it can be used, i.e., it "works" / is in working order. Whether the item in question is easy or difficult to use is addressed in your second question...
2. "Ease of useage" (Note: Better = "ease of use", often in American English rendered expressed as "user friendly"). This statement assume a device, item, etc., that one "uses" is functional, i.e., "works" correctly, but is trying to determine if the device is "easy" to use (understand, operate, etc.) or not easy to use, i.e., difficult to use, complicated, not a user-friendly device, software application, tool, etc.

Note both concepts do not mean the same as (in French) "utile", which in English = "useful". The term "usability" would lean more toward the French term "fonctionnel" and "ease of use" would likely = "facilité d'utilisation" or something along those lines.

it's funny: I live in France but if you were a Russian speaker I could give you "native language" equivalents for these English expressions that would be exact matches; much trickier to accomplish this w/ French, an incredibly "nuanced" language when it comes to "deep meaning" of so many expressions. (Which is why I strive to communicate in French as simply as possible!!!) -- exRanger (edwin)

It makes me think of games – some games are incredibly usable despite being initially difficult. For instance, you might struggle at first with a game like Slope Unblocked, but once you learn the controls and physics, you find it’s designed in a very usable way, allowing you to achieve a high level of skill and satisfaction. Ease of use for that game might be just understanding how to steer the ball initially. Good point, and well explained.

Usability is a broad and comprehensive concept that refers to the overall quality of a user’s experience when interacting with a product. It includes how effectively and efficiently users can achieve their goals, how easily they can learn to use the product, how often they make errors and how easily they recover from them, and how satisfied they feel with the process. Usability is a core concept in user experience (UX) and human-computer interaction (HCI). It is not limited to the surface-level simplicity of a product, but rather encompasses a holistic view of how well a system supports users in accomplishing their tasks. On the other hand, ease of use, also referred to as ease of usage, is a more specific and narrow term. It typically describes the user’s perception of how simple and straightforward a product is to operate. It often refers to the first impression or initial learning curve—how quickly a new user can figure out how to navigate the system, understand its features, and begin using it without confusion. While ease of use is an important component of usability, it is not the whole picture. To illustrate the distinction, consider a software application. A product with high ease of use might be very simple to navigate at first, with clear icons and minimal setup. However, it might lack depth or functionality, leading to frustration as the user tries to complete more complex tasks. Conversely, a highly usable product may take a bit longer to learn initially but ultimately allows the user to perform tasks quickly, with few errors, and with high satisfaction over time. @Speed Stars Unblocked