Final answer:
The assignment of aliases in SQL makes queries more readable, differentiates between same-named columns or tables, and is particularly useful in complex queries or self-joins.
Step-by-step explanation:
The purpose of assigning aliases to Source tables and columns in SQL (Structured Query Language) is primarily for convenience and readability. When dealing with complex queries, particularly those involving multiple tables or joins, aliases can make the SQL statement more readable by providing a short, meaningful name in place of potentially long and cumbersome table or column names. Additionally, when the same table is joined to itself, or when two columns have the same name from different tables, aliases are essential to distinguish between them. It also can make queries more concise and easier to write, especially in repeated references to the same table or column within a query. Furthermore, certain operations, like self-joins, require the use of aliases to differentiate the same table's instances in a query.