While you binding XREF at autocad you asked to chose between bind or insert. what is the difference?

If you "BIND" the xref, all of the changes stay intact, and all of the layers get named according to the xref drawing's name combined with the object's original name, to keep them separate from similarly named objects in the host drawing.If you "INSERT" the xrefs, all duplicate-named layers, blocks, etc. will merge with the host drawing's ones, and no new layers or blocks will be added, unless they have new names.