Few decades ago all the investors was acquiring stocks calling to broker by phone or using some other way to contact him. However, computerization of the world has changed investing significantly. Online investing became more and more popular, meanwhile online investing is more popular now between individual investors than traditional investing. The institutional investors may still use a brokers (not those who are trading online) services for a large scale orders, because a big stake of company‘s stock in demand of supply may affect stock price in an unwanted direction.
Online investing has some advantages compared to traditional investing. The main one is the speed of transaction – the condition in stock exchange changes very quickly and every minute to wait can affect the price of acquired share. When investing online – the order goes to the exchange the same second when you put in on the computer. If you would call broker, even if in hurry it would take a while until your order would reach the exchange. Also online investing is more exact – you put your order exactly how you want to be it by yourself. Sometimes happens when investors are not completely satisfied with conditions of brokers completed transaction.
But traditional investing also has some advantage vs. online: especially that should feel beginner investors, because they can lose money on some stupid mistake when giving wrong order to the exchange (mistaken price etc.). The experienced broker should protect from such beginner mistakes. Also a professional broker may give some investment recommendations, but that is another topic...
Online investing is also most of the times has lower costs, because of lower commissioning fees, what is serious argument when choosing a trading platform. Most online trading platforms will allow you to buy not only stocks, but also bonds, mutual funds, ETFs, derivatives, foreign currencies.
Even if you prefer online investing, doesn‘t mean that you will totally escape traditional investing. If you are investing globally, it will be hard to find a brokerage firm that would allow you to reach the entire world markets online (Bulgaria, Nigeria, Slovakia or other small investment markets), because even the largest firms cover mostly the main markets.