"Sintering" relates to the manufacturing process of the pad material. The other common ones seen are described as "organic". Both have pros and cons in how they perform and last. Sintered pads tend to be more expensive and as they tend to be harder some people find they give the discs are harder time, wearing them out prematurely. The key thing is to buy a recognised brand, (EBC, Brembo, Bendix, genuine Suzuki etc.)and probably based on feedback from forums like this and avoid the cheap obscure branded ones found on the internet, some of which may turn out to be very poor. Would also suggest giving the calipers (pistons and seals) and slider pins and thorough clean and check over at the same time and if the brake fluid hasn't been changed in the last 3 years, changing it as well.
