# What is “temporal depth”?

I need some explanation about the following paragraph (page 3) from the paper A Novel Approach for Robust Multi Human Action Detection and Recognition based on 3-Dimentional Convolutional Neural Networks.

We introduce a 3D convolution neural network with the following notations: $$I(x, y, d)$$ as an input video with a size of $$x y$$ and $$d$$ the temporal depth

What is "temporal depth"? Is it the number of frames?