A tax lien is a legal claim filed in court by a government agency against a person or business owing taxes. Tax liens normally attach to money or property to pay the taxes. A list of tax liens properties on which the taxes has not been paid are kept at the county courthouse along with the proper and complete documentation to avoid any legal problems afterward.
Every year properties are taxed for their value and every year plenty of people fail to pay their taxes on time, incurring taxes and plenty on themselves either due to the financial issue or they just misplaced the tax bills. If you are late to pay your dues then the government seeks investors to balance their budget. Tax Liens can be filed for income taxes, unemployment taxes, sales taxes, real estate excise taxes, Social Security or disability taxes. Once the tax lien is paid, papers are filed with the courts, affirming the discharge of the property.
Many investors invest their assets in the hope that they will be getting huge profit through it but in spite there lies some awful fact which must be known especially (if you are a investor) in order to avoid any complication, one disaster discussion of investment can wipe out your whole capital and your enthusiasm from all this kind of investment.   
The first step should be of building a profitable portfolio of tax liens to your self only to decide the basic purpose of your tax lien investment. Developing a portfolio will surely answer your most critical question like why do I want to invest in tax liens in the first place? Also your reason for investing will determine what type of investment will be best for you.
With the passage of time the tax lien auctions business got huge popularity, most probably because of the abrupt turning of the real estate market and worst jumping down of the stock market which has remained unstable for some time thus compel investor to see some other ways through which they can get a healthy positive outcome with huge benefit. Although profit in tax liens is slow but still it is a hidden secret to the investors. Investing in tax liens assures that your capital will go towards something that is profitable and with a set time period where you can anticipate realizing your profit. Only you have to learn the fundamental principles which are golden and yet very essential to acquire hefty profit. Also try to get more and more knowledge to strengthen your foundation in tax lien business, which could be done through the acquaintance with the property laws, ordinance and so on.