A secured loan is secured against some or all of a borrower's assets decreasing the risk associated with the loan. If the borrower defaults on the loan, the lender may get some/all of these assets in order to cover the loan payments.
Piece of paper that proves ownership of stocks, bonds and other investments.
Shares and equities refer to the same thing - a share in the ownership of a company and entitlement to any distributions (eg dividends).
Any security traded on a public exchange including fixed interest or equity securities.
Funds specifically designed for people saving for their retirement. They are in the form of retail funds available to all savers, or employer funds available only to employees of the sponsoring employer.