When I first started learning botany, the vocabulary was a little confusing. Not only was I having to memorize unfamiliar words and definitions, but I found that different books used different terms to describe the same thing.
Here’s a hint: choose a descriptive word you like and stick to using that one. Becoming familiar with other words that someone else may use is easier after you have the concept down pat.
I recommend the book Newcomb’s Wildflower Guide and Botany in a Day for more details on botany and plant identification (these are the books we use in our fundamentals of holistic herbalism program).
Entire leaves have smooth leaf margins (edges):
Toothed leaves have regular, shallow indentations (including wavy and scalloped)
Lobed leaves have deeper indentations like oak and maple
Heart-shaped and arrow-shaped leaves are a type of lobed leaf, but their indentations are only at the base