Capital markets is a general terms that refers to all markets that a company might access to raise capital or money. This includes both the stock market and the bond market since a company may sell either equity (stock) or debt (bonds) to accomplish this. Traditionally, access to the capital markets was accomplished through a broker/dealer or an investment bank, which would use its relationship with the company and the markets in order to maximize the success of the offering. Further, it would either sell the shares in house or market them through affiliates to make sure that all of the offer was fully subscribed (fully purchased).
The internet has changed this but only slightly so far as it still is a relationship=heavy endeavor to coax the company into offering more debt/equity and to get the investors to purchase them.