Cash Account:

The cash account is the simplest account, does not allow overdrafts, does not allow short selling of stocks, and can only be traded using funds deposited by itself.

The cash account is T+2, that is, after T-day buys the securities, it can be sold on T+2 days.  Similarly, the funds for selling securities on T-day must wait until T+2 settlement before they can buy the securities again or transfer out to the bank account.This type of account has a lower minimum capital requirement for opening an account, and is generally suitable for investors who is beginner or who do not want to conduct complex transactions.

Margin Account:

A margin account allows you to borrow cash to purchase securities. The loan in the margin trading account is collateralized by the securities you purchase. While you hold securities using margin, if the value of the stock drops significantly, the account holder will be required to deposit more cash, more marginable securities, or sell a portion of the securities to maintain the minimum margin requirements. You may also trade in a margin account with your own cash. No extra interest or fees will be charged if you do not borrow money or exceed your cash buying power. Certain trading behaviors are allowed only in margin accounts, such as: short-selling, day-trading, and advanced option strategies.