I'm student of computer science (BS) and considering computational science as the field to major in for MS program.I have two questions which might look silly but I'm really confused:1- Are Scientific Computing and Computational Science fields the same?. In Iran we just have Scientific Computing as an MS program in computer science. After searching for days in Google I saw there were some websites stating that Scientific Computing and Computational Science are the same...2- Is Computer Science a good major to enter computational science?. We have many courses in Numerical Mathematics, Algorithms, and Programming  in CS but it seems like you need good background in physics or chemistry. I feel that it's a major for Mechanical engineers or physicists.
General question about Computational Science
computational physics
Scientific Computing and Computational Science are the same field.  Both involve using computation to answer scientific question through numerical methods.Almost all technical fields can lead into computational science.  Very few people at the end of their undergraduate degree have all the skills needed to be successful in this field.  For instance, I got my undergraduate degree in mechanical engineering, which meant that I had a strong understanding of the physics, but my programming and algorithm knowledge was relatively weak.  I had to pick most of this up as I went.  For you it would likely be the opposite, with you needing to learn the physics.  My experience is that this is not significantly more ground to make up than the average graduate student needs to learn when they join any other (non-computational) lab.In fact, computational science as a program is actually more common in computer science and mathematics departments, since the engineering and physical science departments are usually more focused on what question is being answered rather than how it is being answered.