Issue of debentures:
It means that company is taking loan from public and it will pay them interest on fixed rate at fixed dates. Also, it will return their money (i.e. loan taken) after some time (usually some years).
Company will issue certificates to persons who have given loan. These certificates are the proof that those persons have given loan to the company.
.
.
Redemption of debentures:
It means the repayment of loan amount to those who gave it. So, company is paying the amount back.
Premium on redemption: It is the repayment of debentures in excess of their face value. The company is paying more than the face value.
