difference between hard time and soft time RTOS

[Parth86]

I am looking information about hard time and soft time RTOS
hard time in which system response time is very critical
soft time in which system is tolerable within certain time limit

what is difference between hard time and soft time RTOS?

 

[moffy]

Soft time, like linux, even as a pseudo real time OS will have variable and sometimes significant delays in responding to an external interrupt, can be of the order of ms. Real time OS has a guaranteed maximum response time to an external interrupt, normally of the order of 10s of us.