There are basically two categories of financial risk: The first is referred to as Systematic Risk.
Systematic risk influences a large number of investments across a wide spectrum. The financial crisis of 2008 would be a good example. Virtually, every asset was impacted adversely. This type of risk is almost impossible to protect against. In other words, sometimes lightning strikes.
The second is referred to as Unsystematic Risk, also commonly called "Specific Risk."
This is the type of risk that impacts a smaller number of investments across a narrow spectrum. An example of this would be a highly regarded company using dubious financial practices (think Enron). Proper diversification is the key to providing protection from this type of risk.
Now let's explain in more detail the specific types of Unsystematic Risk that exist in the world of investing.
Market Risk
This is the type of risk that you may be most familiar with. It is simply the normal fluctuations in the price of an investment. It is most apparent in stock-related investments.
Simply put, it is the risk that an investment will decline in value, due to market forces. This is also sometimes referred to as volatility, which is really the measure of market risk. These movements in markets are what provide the ability for an investor to make money.
Credit Risk
This is also referred to as default risk. This occurs when a person or entity (company/government agency, etc.) is unable to pay what they owe on their debt. It can be either the principal or the interest. Corporate bonds tend to have a higher risk of defaulting but tend to pay higher rates of return in an attempt to compensate. Government bonds tend to have lower default rates but pay a lower rate of return. If a bond is considered (by a rating agency) to have a relatively low likelihood of risk of default, then it is referred to as investment grade. Conversely, If a bond is considered (by a rating agency) to have a relatively high likelihood of default, then it is referred to as a junk bond. This is somewhat of a misnomer, since "junk bonds" can be a solid addition to an investment portfolio and can mitigate other types of risk.
Country Risk
This refers to the risk that is inherent when a country cannot meet its financial commitments (think Greece). When a country defaults on its obligations, the impact is often that of a cascading nature. That means not only will the bonds of the country be affected but also other financial assets within the country, such as the overall stock market. In addition, other countries or companies that do business with the defaulting company can also be impacted.
Foreign-Exchange Risk
Investing in foreign countries provides many advantages, especially in terms of diversification. When you invest in assets or debt of foreign countries, note that the currency exchange rates can change the price of the asset or debt. So, even though the asset increases in value when you exchange it for your home currency, you could suffer a loss. The converse is also true: the asset could go down, but when you transfer it into your home currency, you could also realize a gain.
Interest Rate Risk
This refers to the risk when a change in interest rates affects the value of an asset or debt instrument. Typically, the risk applies to bonds in a more direct fashion than it does to stocks. However, stocks, especially preferred, convertible and high dividend ones, can also be affected. With all things being equal, as interest rates increase, the value of the bond will decrease.
Political Risk
This refers to the risk that occurs when the policies of a country change, especially if it happens in a random manner. For example, if a company is selling in country ABC and that country radically changes its tax laws and becomes business unfriendly, companies that do business in that country can be adversely affected.