Logically, they are the same, they both perform a logical AND. However, all AND operands are evaluated without using conditional optimizations, whereas THEN IF uses optimizations.
Say you have conditions A true, B false, and C true.
A AND B AND C = false
A THEN IF B THEN IF C = false
The difference is that when using AND, all A, B, and C get evaluated, so if C has individual actions on true, they will run. When using THEN IF, only A and B will get evaluated, C will be skipped as the overall result is now known to be false. So if you had individual actions on C, they won’t run, because C never gets evaluated.
Hope I didn’t confuse more…