These are short periods of employment, usually taken over the summer (note that Graduate Internships are also available for when you have completed your studies). They will be advertised all throughout the academic year for the following summer, although the bigger companies tend to advertise in the autumn so make sure you are ready!
Employment 4 Students
Some internships can be undertaken virtually if you are unable to travel to conventional opportunities.
Prospects website - virtual work experience
Browser does not support script.