I came across Algebra from Artin and Higher Algebra by Hall & Knight and even though they both have kind of same title I found them entirely different. H&S talks mostly of ratios, proportions and polynomial equations whereas Artin talks mostly in terms of Matrices, he talks even of Permutations in Matrices.
If both are Algebra then why they are so different ?
P.S I have just started self-study of Calculus, Linear Algebra, Statistics and Probability for my Data Science and Machine-Learning course. Artin looks much more modern and "in the context" of all these topics. (Topics in Algebra by Herstein too looks more modern and usable for me)
The word "algebra" bears different meanings in mathematics. It can be high-school algebra, i.e., solving equations, manipulation of algebraic expressions etc.
It can also mean abstract algebra, i.e., dealing with algebraic structures like group, ring, field.
In Bourbaki's point of view, in modern mathematics, it is composed of analysis, algebra, and topology.