Is "algebraic system" the same as "algebraic structure"?

Question

1.

algebraic system | planetmath.org:

http://planetmath.org/algebraicsystem

It seems that algebraic system is only a set on which some operations are defined. Is it necessary that some additional conditions hold? like commutativity, associativity.....?

2.

Elements of Modern Algebra By Linda Gilbert 3.1
p.141

http://tinyurl.com/q5qvgff

It seems say "algebraic system" and "algebraic structure" are the same.

I am confused.....

Answer 1

They're the same. $\;\!\;\!\;\!\;\!$

It seems that algebraic system is only a set on which some operations are defined. Is it necessary that some additional conditions hold? like commutativity, associativity.....?

No additional assumptions are required.