Financial freedom is the main pillar of all the freedoms that you may possess. Without it you would be obliged to follow the orders of other people who pay you money for your job or vote or support of their cause. No financial freedom means no any other freedom for you at all.
Financial freedom means that you have money independently of whether you are working or not. It means passive income or having a lump sum of assets enough to live for, say, 50 years in the future. These assets and incomes should be independent of inflation.
To protect your future from black swans your assets and income should be diversified - thats the only available protection, as nobody knows the future and only covering the field can somewhat guarantee some stability.
Creating income stream usually means sacrificing some current consumption for the future income. Saving and investing works wanders on longer timeframes because of the nature of compounded interest.