Ideally, the free press in a democracy should do the following:

• Allow the different points of view in political debate to appear and to debate each other (different political parties and different candidates each with their own ideas qbout how best to govern the country)
• Facilitate the accountability of elected officials: elected officials have to present their achievements before the next elections, and opposition candidates have to criticize these achievements
• Expose wrong doing by elected officials and their appointees (investigative journalism in the style of “Watergate”)
• Reflect public opinion in general, especially new public concerns which haven’t yet made it into the political debate.

A prerequisite for all this kind is pluralism in the media and the absence of information monopolies; the absence of government control on the media or control by wealthy groups which want to push their own agenda; critical and unbiased journalists; protection of sources in the case of investigative journalism; airtime for political debate; restrictions on political publicity in order to guarantee equal airtime for less wealthy groups…

More on the freedom of the press.