The difference between both code snippets is the dimension of channels vs. length.
For Conv1d the input dimensions are defined as [batch, channel, length].
In this example you are creating an input with 200 channels and a length of 4.
Since your stride is set to 1, you will get an output dimension of 2.
Try to visualize the operation using the link above.
What exactly is your use case? Could you explain a bit what you would like to achieve?