This is also known as digital forensic science. Definition of Digital forensics is that it deals with finding out and investigating the digital data which is found in electronic or digital devices. Lets say Police have recovered a CD or any disc which is containing some important clues for investigations, the digital forensics examiner shall be called to find out the data stored in that CD or disc.
Digital forensic expert or examiner could use different tools for recovering the data. This is basically a very expert field which requires a specialized training along with a degree to have some grip on this field. Digital forensics jobs are increasing day by day as courts have started to give good thought to these investigation methods.
Salary of digital forensic is generally on the higher side as compared to another fields as these require higher skill and expertise. These are various certification courses and software available these days. Overall, it an exciting field yet very challenging one as it is very difficult to prove the findings in the courts of law.