Column 1. All four charts identify the type of preference in the first column. This is where you begin determining your place in the line. You need to look to see which category applies to you.
Column 2. This column is labeled “All Chargeability Areas Except Those Listed” on all four charts. It is your place in line. If your priority date is before this date (unless you are from a country listed in the other parts of the chart), you can proceed to file for a green card or an immigration visa. You can also proceed if the column is marked C.
Columns 3, 4, 5, 6, and higher numbers. These columns are for those people who live in the identified countries. There are different cut-off dates for people from China, India, Mexico, and the Philippines. Other countries may be listed too. For example, the employment charts for the December 2020 Visa Bulletin list El Salvador, Guatemala, and Honduras (in one column) and Vietnam (in another column).
Here is the Final Action Date “Family” chart for the December 2020 Visa Bulletin.
[It’s up to you if you want to copy and paste the other charts.]