This equals method is checking to see if the argument is some incompatible type (i.e., a class that is neither a supertype nor subtype of the class that defines the equals method). For example, the Foo class might have an equals method that looks like:
public boolean equals(Object o) {
if (o instanceof Foo)
return name.equals(((Foo)o).name);
else if (o instanceof String)
return name.equals(o);
else return false;
This is considered bad practice, as it makes it very hard to implement an equals method that is symmetric and transitive. Without those properties, very unexpected behavoirs are possible.