One thing with paying taxes is that even if you don't go to the tax offices to pay then as your duty as a citizen implies, you will pay it one way or another from purchasing items that are taxed already.The difference between tax and revenue is that tax is a compulsory payment made to the government by individuals and business owners living in the country while revenue is money you generate by doing business.
And again the aspect of revenue thais acuring to government might not just be coming from utilities payment from citizens or from their salaries,government might have stake in some investment or in multinational coy that will be bringing in revenue.Tax is usually the money government collects most times mainly from salaries,utilities and some basic produce within a country,and this is what the government use to fulfil its obligations to its citizen,then the revenue is the various forms of money coming into government coffers.