In a similar fashion to government Gilts, corporate bonds are a way of borrowing funds, except that these investments are issued by multinational companies as opposed to the government. These often offer better returns than government gilts, since the risk of a company, even a multinational one, going bankrupt is greater than the risk of a government being unable to repay it’s debt.
Like Gilts, Corporate Bonds often form a part of professional investment portfolios, since fund managers can use these to spread risk and provide income.