In brief, CrystalDiskInfo is a free HDD/SSD utility application to monitoring health status, temperature and control AAM/APM settings. Generally, it supports S.M.A.R.T. information and a part of USB-HDD.
In short, S.M.A.R.T. Information consist of Read Error Rate, Spin-Up time, Start/Stop Count, Reallocated Sector Count, Seek Error Rate, Seek Time Performance and Others.