Glad to. Thanks for admitting that you don't know the difference. You are not alone on this forum, I assure you.
Evolution is the theory that species evolved from each other, which explains fossils of species no longer seen living on Earth.
Darwinism is an explanation for how species evolved from each other. It consists of four main parts:
Variation, inheritance, selection, and time.
Variation: while most offspring will be very similar to their parents, occasionally an individual is born/hatched/seeded that has a slight or significant difference. For example, an animal similar to the giraffe, but with a much shorter "normal-sized" neck, might give birth to a mutated calf with a longer neck.
Inheritance: That mutation is passed on the offspring of that mutated individual, and in turn to their offspring. So more and more slightly longer-necked animals appear.
Selection: The mutation is beneficial to the mutated individual and his progeny in that it allows it to survive and reproduce more so than its non-mutated peers (because he gets more leaves!). So much so that the mutated offspring take over the habitat, move to another habitat, or force the original short-necked animals to find another habitat.
Time: Given enough time, similar neck-elongating mutations occur (each independent of the one before it), and lead the modern giraffe. It was similar processes that led to the origin of all species on Earth.
If any Darwinists thinks that is inaccurate, I welcome them to give their own explanation.