What does the error "Parse error: parse error, expecting `','' or `')''" in PHP indicate?

The error "Parse error: parse error, expecting `','' or `')''" in PHP indicates that there is a syntax error in the code, specifically a missing comma or closing parenthesis. To solve this issue, carefully review the code where the error is occurring and ensure that all commas and parentheses are correctly placed.

// Incorrect code causing the parse error
$variable = someFunction(1 2);

// Corrected code with the missing comma added
$variable = someFunction(1, 2);