Question

What is the Difference between the two?

SELECT [EmployeeList].[Emp_ID], [EmployeeLevel].[LevelPosition]
FROM [EmployeeList], [EmployeeLevel]

---

SELECT [EmployeeList].[Emp_ID], [EmployeeLevel].[LevelPosition]
FROM EmployeeList INNER JOIN EmployeeLevel ON 
[EmployeeList].[LevelID] = [EmployeeLevel].[LevelID]

regardless of the field names.

Answer 1

The first one is not correlated in any way and will return a cross join / cartesian join with every permutation of rows from the 2 tables. You would need to add a WHERE clause

SELECT [EmployeeList].[Emp_ID], [EmployeeLevel].[LevelPosition]
FROM [EmployeeList], [EmployeeLevel]
WHERE [EmployeeList].[LevelID] = [EmployeeLevel].[LevelID]

Then they would be semantically the same but the above is the old style ANSI syntax and is largely discouraged by everyone except Joe Celko due to being less clear and the possibility of causing inadvertent cartesian Joins (as well as being more work to change if you want to convert to an outer join).