What is a combination reaction?

When an iron rod dipped in a solution of copper sulphate, a redox reaction occurs:
$\mathrm{Fe}+{\mathrm{CuSO}}_4\to {\mathrm{FeSO}}_4+\mathrm{Cu}$

(i) Which one is reduced and which one is oxidised?

(ii) Which one is the oxidising agent?

Below are given two chemical reactions. Which is combination reaction and which is displacement reaction?

(i) $2\mathrm{KBr}\left(\mathrm{aq}\right)+{\mathrm{Cl}}_2\left(\mathrm{aq}\right)\to 2\mathrm{KCl}\left(\mathrm{aq}\right)+{\mathrm{Br}}_2\left(\mathrm{aq}\right)$

(ii) $\mathrm{Fe}\left(\mathrm{s}\right)+\mathrm{S}\left(\mathrm{s}\right)\to \mathrm{FeS}\left(\mathrm{s}\right)$