Restructuring, renegotiation, repurchase of mortgage loan: what differences?

Because the world of credit is sometimes opaque, financial company explains the differences between certain transactions. Credit repurchase, loan consolidation, renegotiation… If the names are similar, the operations differ. Restructuring, repurchase of mortgage, grouping of loans: how does it work? Did you think that the repurchase of credit only concerned real estate or was the