Real time systems are those systems that work within strict time constraints and provide a worst case time estimate for critical situations. Embedded systems provide a specific function in a much larger system. When there is an embedded component in a real time system, it is known as a real time embedded system.
There are primarily two types of real time embedded systems i.e. hard and soft. An illustration to explain this further is −
This type of system makes sure that all critical processes are completed within the given time frame. This means that all the delays in the system are strictly time bound. Also, there is little to no secondary memory and data is stored in short term memory or read only memory. Hard real time systems are used in various areas such as missiles, airplanes etc.
These are much less constrictive than hard real time systems but the basic premise is the same i.e critical processes need to be completed within the given time frame. However, this time frame can be a little flexible. Soft real time systems are used in various areas such as multimedia, scientific projects etc.
There are various applications of real time embedded systems. Some of these are −