I am getting confused between Append and Multiply Node, Like whats the exact difference?
When do I need to use them?
AppendVector
The AppendVector expression enables you to combine channels together to create a vector with more channels than the original. For example, you can take two individual Constant values and append them to make a two-channel Constant2 Vector value. This can be useful for reordering the channels within a single texture or for combining multiple grayscale textures into one RGB color texture.
Multiply
The Multiply expression takes two inputs, multiplies them together, and outputs the result. When you pass color values as input, the results are similar to the results of the Multiply layer blending mode in Photoshop.
If you pass values with multiple channels, each channel is multiplied separately. For example, if you pass RGB color values to each input, the R channel of the first input is multiplied by the R channel of the second input and the result is stored in the R channel of the output; the G channel of the first input is multiplied by the G channel of the second input and the result is stored in the G channel of the output, and so on.
Both inputs must have the same number of values, unless one of the values is a single float value. In that case, each channel of the multi-channeled input is multiplied by the single float value, and stored in a separate channel of the output value.