Again, here are the 4 words I would use when describing the essence of Computer Science, in order of significance:

• Abstraction
• Automating Abstractions
• Implementing Automated Abstractions
• Efficiently Implementing Automated Abstractions

Note that I purposely didn’t use either the word ‘computer’ or ‘science’ in my summaries, since I don’t think they properly embody the essence of the field.