<s>
A	O
persistence	B-Library
framework	I-Library
is	O
middleware	B-General_Concept
that	O
assists	O
in	O
the	O
storage	O
and	O
retrieval	O
of	O
information	O
between	O
applications	O
and	O
databases	O
,	O
especially	O
relational	B-Application
databases	I-Application
.	O
</s>
<s>
Many	O
persistence	B-Library
frameworks	I-Library
are	O
also	O
object-relational	B-General_Concept
mapping	I-General_Concept
(	O
ORM	O
)	O
tools	O
(	O
e.g.	O
</s>
<s>
Hibernate	O
,	O
MyBatis	B-Library
SQL	O
Maps	O
,	O
Apache	O
Cayenne	O
,	O
Entity	B-Application
Framework	I-Application
,	O
Slick	O
,	O
and	O
Java	O
Ultra-Lite	O
Persistence	O
)	O
.	O
</s>
<s>
The	O
mappings	O
can	O
be	O
defined	O
using	O
either	O
XML	B-Protocol
files	O
or	O
metadata	O
annotations	O
.	O
</s>
