Answer to Question 1
A credit card, such as a Visa or MasterCard, has a spending limit based on the users credit history; a user can pay off the entire credit card balance or pay a minimum amount each billing period. Credit card issuers charge interest on any unpaid balance. Note that a consumer is protected by an automatic 30-day period in which he or she can dispute an online credit card purchase.
A debit card looks like a credit card, but it works quite differently. Instead of charging purchases against a credit line, a debit card removes the amount of the sale from the cardholders bank account and transfers it to the sellers bank account.
Answer to Question 2
Mobile telephone carriers are currently the most widely used small payments services. Buyers make their purchases using their mobile phones and the charges appear on the buyers monthly mobile phone bill. The use of this micropayment system has been held back by the mobile carriers substantial charges for providing the service, which can amount to 30 percent of each transaction. The company that offers the service typically takes another five percent, thus the buyer can end up paying substantially more than the actual value of the purchase. One of the largest small payments markets today is for music downloads. Most of the music and smartphone software downloads sold by Amazon and Apple (iTunes) are paid by credit card. Sales through the Google Play store are primarily paid as charges on the customers monthly mobile phone bill.
rRNA processing
How to choose the right payment plan with changing conditions (Question 1)
How to calculate credit card interest when the interest is compounded
Morphological differences in shell characteristics and head colouration patterns
What is the differences between RNA seq and RAD seq?
Stages in memory processing.