Algebra courses in high school are foundational mathematics courses that introduce students to the principles of algebraic thinking and problem-solving. These courses build upon the arithmetic skills developed in earlier grades and introduce students to the use of variables and symbols to represent mathematical relationships. Algebra is an essential subject in high school, and its concepts are widely applied in various fields, including science, engineering, economics, and computer programming. The algebra curriculum typically progresses from basic to more advanced concepts throughout high school.