What is ldap.h?

["Soheil Shaghaghi" <soheils@jhanna.com>]

Hi everyone,
I am trying to install pam_ldap, and nss_ldap on a FreeBSD server.
No matter how I go about it, it keeps giving me errors during the
configure:
configure: error: could not locate <ldap.h>

I was referred to OpenLDAP to solve my problem. However, I was told to
install the developers package.
I can't find anything regarding this on the OpenLDAP site. All I see is the
LDAP Server.

Could someone please tell me what I need to do to get these installed.

Thanks so much,
Soheil