cell protection
Data is considered invalid when it is wrong or has changed. Data represents facts that are recorded, so any alterations made to it can make it invalid.
When you tap the ESC key while entering data into a cell, it cancels the current entry and returns the cell to its previous value. It is useful when you want to discard the changes you made without saving them.
Once the cell is selected, then you can just start typing. See the related question below.
Yes. If you press ESC before entering typed data into a cell (e.g. press ENTER), the cell will return to the same condition as before you started typing.
There are hundreds of reasons. You press the Enter key when you want to execute whatever command is appropriate at the time. If you are entering data in an Excel worksheet cell, you can press the enter key when you are done entering the data.
Data types for entering records depend on the nature of data
The term invalid data can have lots of meanings. Access won't accept things like trying to type text into a number field, as that is clearly invalid. However, unless you specify values that are invalid for a number field, like setting a maximum value that can go in, then it will accept it. So some invalid data is determined by Access, such as the wrong data type in a field, and some invalid data is determined by the user who wishes to only allow certain data in certain fields. Implementing that kind of validation is down to the person designing the database. There are many ways of doing that and that is part of the skill of the designer of the database and clearly specifying in the design what data is valid and what is invalid.
It means typing something as text, numbers, dates etc. into a cell, but excludes typing in formulas.
I have not heard that term in reference to Excel before, but since the cell you are working on is called the active cell, then I support a passive cell would be any cell where you are not entering data. Another meaning could be those cells that contain data, but do not interact with any other cells (are not included in a formula and do not hold a formula).
Often it's simply referred to as invalid data or even garbage data. If it's data that was once valid but is now invalid or unrelated to other data, it might be referred to as orphaned data or an anomaly.
You can type direct into a cell or into the formula bar. If you have a database set up, you can also enter data in using a form. Data can also be entered quickly by using facilities such as Autofill and using formulas.
data entry