public class RenderExampleClass {
    /****get set varaible which will carry the true or false condition to the page****/
    public Boolean showPanelHistory{ get; set;}
    /****get set varaible which carry the list of accounts to the page****/
    public Account accountList{ get; set;}

    /****Acction method which is used in the page which acts like switch*****/
    public PageReference showpanel(){
       if(showPanelHistory == false) {
            showPanelHistory = true;
        }
        else if(showPanelHistory == true){
            showPanelHistory = false;
        }
        return null;
    }
    /***Example methos that to query the list of accounts***/
    public void accountList(){
        accountList = [
            SELECT  Id,
                    Name,
                    Type
            FROM    Account
            ];
    }
    /***** Setting up showPanelHistory = false directly in constructor
    so when page loads the switch willl be in false condition********/
    public RenderExampleClass() {
        showPanelHistory = false;
    }
}