What is the bss section of an image?

I am trying to understand PE file formats and there are many sections. What is the bss section? Is that fluid and data written to that sect开发者_如何学Cion can be overwritten anytime? Is that a storage location in memory of the loaded binary?

In assembler, the bss section was used to define memory space that didn't need to be initialized to any particular value. I imagine it hasn't changed.