In Excel, how to copy formulas without changing the reference position-relative reference and absolute reference

Reference from: http://blog.pchome.net/article/253011.html

In an Excel worksheet, cell references of a formula are classified into relative reference, absolute reference, and hybrid reference.

"Relative referenceIn the cell formula, the column label and row number are used to directly represent the address of the referenced cell. When you copy a formula containing the cell address to a new cell, the address referenced by the formula in the original cell changes in the new cell, however, the distance between the referenced cell addresses remains unchanged.
"Absolute reference", That is, the absolute cell reference in the cell always references the cell at the specified position. If the position of the cell where the formula is located changes, the absolute reference remains unchanged. If the formula is copied in multiple rows or columns, the absolute reference is not adjusted.

Use "absolute reference" in the formula, and add the "$" symbol before the row number and column label of the referenced cell.(Note: You can add the "$" symbol before the row number or column label to fix a column or row)Indicates the exact address of the cell referenced in the formula. It is irrelevant to the location of the cell containing the formula. The cell with the "$" symbol is used for calculation regardless of the cell, all referenced cell data after the "$" symbol. "Relative reference" and "absolute reference" can be used in combination, that is, "hybrid reference". The cell value referenced by cell operations changes with the "relative reference" row number or column name.

A hybrid reference has an absolute column and a relative row, or an absolute row and a relative column. An absolute reference column is preceded by a $ symbol. The absolute reference row is preceded by the $ symbol.
When copying a cell, if the formula of the source cell contains a "hybrid reference", the position of the cell where the formula is located changes, the relative reference changes, and the reference remains unchanged, if the formula is copied in multiple rows or columns, the relative reference is automatically adjusted, but the absolute reference is not adjusted.