Discount FActor = percentage at which you discount the estimated cash flows to calculate the NPV of an asset. Zero coupon bond price is priced at a discount when issued and matures at the par value.

Bootstrapping means calculating the Discount Factor from known previous discount factors of smaller maturities and the known rate(yield) of the equivalent maturity. E.g. for known discount factors of 3m and 6m maturities, and knowing the rate (yield) for 1y zero coupon bond, you can calculate the 1y discount factor. This process is iterative and can calculate all the discount factors for known zero coupon yields.

The risk of loss of principal or loss of a financial reward stemming from a borrower's failure to repay a loan or otherwise meet a contractual obligation. Credit risk arises whenever a borrower is expecting to use future cash flows to pay a current debt. Investors are compensated for assuming credit risk by way of interest payments from the borrower or issuer of a debt obligation.

Liquidity Risk - asset liquidity risk - ability to raise the necessary cash to roll over its debt or to meet the cash margins etc.

Strategic Risk - significant bank investment in a venture, which results in write-off and banks reputation among investors will be damaged.

There are mainly three types of Risks:
1) Credit Risk
2) Operational Risk
3) Market Risk

others are

liquidity risk, interest rate ,foreign exchange risk, country risk, insolvency risk,
Off balance-sheet risk , technology risk, diversifiable and non-diversifiable risk

risk means uncertainty about future events affecting our current positions