"Soft computing" is just automating process of computation. "Hard computing" means you are just doing computation process according to your needs only. For eg. there are kind of problems[identifying vowels and counting them in any given sentence] which a human brain can compute very easily. This is an example of "Soft Computing". Our human brain scans vowels and counts them in seconds. Now coming to "Hard computing" - you make a program for this same above scenario and run it. That is part of "Hard Computing". You are telling the computer -just a box to compute(or process) according to your needs. So that kind of computing is a part of "Hard computing". "Soft computing" is much much times faster than "Hard Computing". Basic constituents of "Soft Computing" include Fuzzy Logic , Neural computing, Evolutionary computation, Machine learning and probabilistic reasong etc.
Hard computing can be made analogy to "Hard Coding" and Soft Computing to "Soft coding"
Hard computing can be made analogy to "Hard Coding" and Soft Computing to "Soft coding"