A line of credit (LOC) is a good option if you need the flexibility of borrowing as needs arise like home improvements, a special trip, education costs, or paying for larger purchases instead of paying with your credit card.
With a line of credit you apply once to determine your approved borrowing limit and you are only charged interest on the portion you use/borrow.
Secured means the line of credit is tied/secured to your owned assets like a home, car or other. This can mean you may be able to borrow a larger amount and at a lower interest rate as there is less risk.
Unsecured means the line of credit is not tied to any assets and can mean a faster approval process but likely at a higher lending rate and can require a better credit score.