Can Hibernate change structure but keep data?

Question

If I add fields to classes and set

<property name="hbm2ddl.auto">update</property>

will Hibernate add field to table with keeping table's data?

Answer 1

<property name="hbm2ddl.auto">update</property> : This will update your db schema without losing your data if you are going to add new columns. But if you change definition of any existing column, then it may loose data.