What is Difference between Tale Aliases and Column Aliases? Do they Affect Performance?

Usually, when the name of the table or column is very long or complicated to write, aliases are used to refer them.

Example:

SELECT VeryLongColumnName col1
FROM VeryLongTableName tab1

In the above example, col1 and tab1 are the column alias and table alias, respectively. They do not affect the performance at all.