Usually that indicates the active cell, but you can also have a selection of cells or have cells that have had borders applied to them.
Active cell.
Active cell.
active cell
the cellis called the judgular vasictomy cell
It could just be a cell with a border around it, or it could be the active cell, which is probably the answer you are looking for.
The dark rectangle that outlines the cell you are currently working in is called the "cell border" or "active cell border." It visually indicates the selected cell in a spreadsheet application, such as Microsoft Excel or Google Sheets, allowing users to easily identify where they are entering data or making edits.
You are referring to the active cell. However, it is possible to change the colour scheme. Also, when constructing a formula, different cells that are referenced are highlighted in different colours, including green. So a cell in a formula can be enclosed in a green border.
In Microsoft Excel, the active cell has a thick line (border) around it. If you type, this is the cell into which your typing will be put as a value (numeric or text) or formula. If you select a range of cells, the cell at which you started making the selection is the active cell. Although the whole range is highlighted, only the active cell has the characteristic border.
If it is the standard one that surrounds all cells, it is a gridline. If it is heavier and made to have the cell stand out, it would be a border.
active cell
The cell borders are highlighted, or if a range of cells are selected, the active cell will be a different colour than the others, usually being white. The name of the active cell will always appear in the name box.
The spreadsheet cell that is currently active and has a heavier black border around it is called the "active cell." This cell is where data can be entered or edited, and it is highlighted to indicate that it is selected. The active cell's coordinates are typically referenced by its column letter and row number, such as A1 or B2.