Foreshadowing: very briefly, here are a few big ideas that we'll see over the quarter. Some of these are intuitive, and some will be a surprise.
An "algorithm" is the idea or plan of how to compute something - e.g. the algorithm to produce a bluescreen image from two images. When you are programming, writing code, you are taking the algorithmic idea and translating it to code the computer understands.
Data is just the passive information, while "code" defines the active plan followed by the computer. A JPEG vs. an "app" on your phone. Both code and data both exist in the dry, mechanical domain in the computer.
The computer runs whatever code it is given mechanically. That is not the same as thinking! Writing code in CS101, you'll get a real appreciation for this idea.
Often the code you write will be quite short. The computer can run the short piece or code over millions of billions of data items. This is a powerful combination - the code has some insight in it, and the computer is good at applying it massively.
Computer hardware gets significantly cheaper and more powerful year after year. E.g. 4 years ago your phone holds 4 GB of data. Now for about the same cost it holds 16 GB (4x more). That's Moore's law.