This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
mysql_fetch_row is the same as mysql_fetch_array with MYSQL_NUM. That is, you get an array with a numeric index.
However, with mysql_fetch_array you can also specify MYSQL_ASSOC, in which case the array is indexed by the column names. And then there is MYSQL_BOTH where you can use either a numeric or column name index.
Using the links Matthew provide, look at how the examples differ for the two functions.