A major is a group of courses required in order to receive a degree –– an area you specialize in, like Accounting or Chemistry. There are certain "core courses" in the specialization that everyone is required to take.
A career is an occupation, trade, profession, or vocation. It refers to what a person does to earn a living.
Career planning is an ongoing process. You can increase your chances of choosing a career that’s the best fit for you by “testing the waters” before graduation. By gaining targeted experience through part-time jobs, volunteering, or internships during college, you can experience first-hand what a career and its working environment is like.