To hide fields in a grid view (or show hidden fields), click the Hide fields button in the view bar to bring up the hide fields dialog. If no fields in the current view are hidden, the hide fields button will resemble an eye with a line through it and say "Hide fields."
If there are any hidden fields in the current view, the hide fields button will have a blue-shaded background and (if the window is wide enough) will say the specific number of fields that are hidden, e.g. "12 hidden fields."
When the hide fields dialog is open, you can see which fields are showing (where the toggle is green and switched to the right) and which fields are hidden (where the toggle is grayed out and switched to the left).
To show or hide a field, click the toggle next to the name of that field.
The Hide all and Show all buttons will let you quickly hide/show all fields (except the primary field, which cannot be hidden).
By clicking and dragging the drag handles on the field names, you can quickly rearrange the order of the fields in your view.
If you have a large number of fields, you can type a search term in the Find a field search box to more easily find the field you're looking for.
Another way to hide a field is by clicking on the field header, then selecting the Hide field option from the dropdown menu.
You can also hide or show individual fields from a grid view by opening up an expanded record.