This is a student's growth portfolio. It shows her progress from the beginning to the end of the year. You may explore this in order to understand how you may want to make portfolios for your future students.
This site explains what a portfolio is and why it is important to create one for yourself. It also describes different sample portfolios and how to arrange a portfolio.
This is a woman's best work portfolio. She is doing her residency at a school and is keeping recordings of her students work as well. Explore this site to get a better understanding and see what you may want to do when you become a teacher or during your student teaching semester