how network actually work?

[anitach2003]

Hi I am pretty new at this area and I have some question

1.after running in clrhead we have this
(prior_embeddings): Embedding(192, 3)
(seg_decoder): SegDecoder(
(dropout): Dropout2d(p=0.1, inplace=False)
(conv): Conv2d(192, 5, kernel_size=(1, 1), stride=(1, 1))
)
where the output of conv will go and whats Embedding mean in this area
2.after that we have reg_modules and cls_modules.this happen after roigather or not and is it give output to roighater?
3.now we have roi_gather.does f_key get the out put of fpn_convs for each layer,what is the input for ROIgather?
4.what is f_query and f_value and W input and output?
5.what is the refined shape ?
6.what is identity mean in network architecture