Before things moved online, all shares were traded through paper certificates. Trading in paper shares is a more expensive and cumbersome option. Online trading is quicker and easier for not only you but also the stockbroker.
As time is money, if you still want to trade in paper share certificates you'll be penalised for this by the broker who'll have to spend more of his time and therefore your money on the trade. So if you still have paper shares, your best option is to convert these to online shares.
Most platforms will allow you to do this at no cost, you'll just have to fill in a form and it will take a few days to convert them to online shares.