“When I use a word,” Humpty Dumpty said, in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.” (LEWIS CARROLL)
Scientists use computers as everebody else, so what is scientific (engineering, technical) computing or programming? I’ll define scientific computing as using of some kind of the field specific libraries (modules or tools) e.g. you read data from the file call functions which process the data and plot the result. Actual program depend on language you use such as Python, Matlab, R, Maple etc. The point is that you need not to implement corresponding numerical algorithms by yourself, this job is already done by module (or library) author. Scientific programming starts when you can not find what you need.