What is the difference between AC & DC current

Question

Accepted Answer

AC current changes direction periodically while DC current flows in one direction only.

AC current is used in household appliances and power grids while DC current is used in batteries and electronic devices.
AC current can be easily transformed into different voltage levels using transformers while DC current cannot.
AC current is measured in RMS (root mean square) while DC current is measured in average value.
AC current is more dangerous to humans than DC current due to its ability to cause muscle contractions.
DC current is more efficient than AC current for long-distance power transmission.

What is the difference between AC &amp; DC current