The key property of a security is its transferability: the right can be transferred to another person together with the document itself without reforming the relationship with the obligated party. This is what distinguishes it from an ordinary contract.
Based on the nature of the certified right, there are equity securities that confirm participation in capital—shares; debt securities that certify an obligation to return funds—bonds and bills of exchange; and instruments that certify a share in an asset, which include sukuk.
Modern issues exist in dematerialized form: there is no physical document, rights are confirmed by entries in the registration system, and identification in trading is conducted using an assigned code. Transfer of rights occurs through account operations rather than by handing over paper.
Common to all types: a security certifies rights but does not guarantee their economic result. It determines what an investor is entitled to claim and in what order, while actual performance depends on the condition of the obligated party.