hi, i was just wondering if anyone can guide me a bit on what this do ?

contract Ownable {
address public owner;

event onOwnershipTransferred(address indexed previousOwner, address indexed newOwner);

/
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
constructor() public {
owner = msg.sender;
}

/
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}

/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param _newOwner The address to transfer ownership to.
*/
function transferOwnership(address _newOwner) public onlyOwner {
require(_newOwner != address(0));
emit onOwnershipTransferred(owner, _newOwner);
owner = _newOwner;
}