In order to answer this question, we first need to define concurrent powers. Concurrent powers are powers that are held by both the federal government and the state governments. These are distinct from powers that are held only by the federal government (for example, regulating interstate trade) or only by the state governments (for example, administering elections).
Perhaps the most important concurrent power is the power to tax. Both the state governments and the national government have the power to impose taxes. This is why, for example, there are state income taxes in many states along with the federal income tax. Both the states and the national government also have the ability to borrow money and to have court systems. Concurrent powers are powers, such as the power to tax, that are held by both the state and the national governments.