Visual aids can really help you understand what domain and range mean in functions. Here are some great tools to use:

1. Graphs: When you plot functions on a graph, you can see how the inputs and outputs relate to each other. The $x$-axis shows the domain, which is all the possible inputs. The $y$-axis shows the range, which is all the possible outputs.

2. Number Lines: You can use number lines to show the valid inputs (domain) and outputs (range). This makes it easier to see which numbers you can use.

3. Tables: Tables are super useful! You can list the input values and their corresponding output values, which helps you understand the relationship clearly.

4. Venn Diagrams: If there are some restrictions on your functions, Venn diagrams can help. They show the groups of valid inputs and outputs in a clear way.

5. Function Notation: Get to know function notation, like $f(x)$. This helps you see which numbers are inputs and which are outputs in a simple way.

Using these tools can make learning about domain and range much easier!