the database for the records that meet the criteria (SKI or  SK2,  Supply  Department,  and  NEC  1234).  The computer  then  displays  or  prints  the  requested information in the format specified. See figure 3-6. You do this through the  query  and report  features  of the database  package.  Doesn’t  that  beat  manually  searching through  a  drawer  full  of  folders,  which  could  take hours? A  database  is  nothing  more  than  a  collection  of data—many   file   folders   or   individual   records containing  several  fields  or  data  elements.  The  database is organized to allow you to retrieve, update, and have ready   access   to   various   information   that   can   be formatted and printed as you desire. The database itself doesn’t  do  anything;  it  just  holds  information. Understanding Database Software To understand how a database program works, you first  need  to  have  an  understanding  of  certain  terms. Some   of   the   terms   you   are   already   familiar   with, whereas   others   you   may   not   be.   These   include database, record, field, pointer, index, primary key, and secondary key.  They are defined as follows: . Database— A database holds information that is related to a specific type of application-payroll, personnel, supply inventory, and so on. In this context, the term  database  is  often  considered synonymous  with  file.  This  is  especially  true when dealing with database files. l Record— A record consists of a group of related fields,   all   pertaining   to   the   same   subject:   a person, a thing, or an event. Figure  3-6.—Example  of  a  database  report. Field—   A   field   consists   of   one   unit   of information. A field is also referred to as a data item or a data element. It maybe alphabetic, like your  name  (John  or  Jane  Doe);  numeric,  like your  ZIP  Code  (01234);  alphanumeric,  like  your post office box or street address (P. O. Box 669 or 1234  Main  St.);  or  logical  (true/false),  like  on leave  (true-on  leave,  false-not  on  leave). Pointer— A pointer is a data item in one record that  identifies  the  storage  location  of  another logically related record. Index—  An index enables you to access records in a database (also referred to as database file or file) in the order of the index regardless of the physical sequence of the records in the database. You  can  think  of  indexing  as  sorting  without having  to  sort. The  index  itself  is  a  file.  It contains a duplicate of the key field (or fields) such as account number, or name and security number, and a pointer to the actual disk record identified  with  this  key  in  another  permanent disk file. For example, if there are 5,000 records in your database, and the key field happens to be SSN,  then  the  index  would  also  contain  5,000 entries with each entry having an SSN. It is also possible for you to have one or more secondary indexes  that  contain  other  various  secondary  key fields. Primary key—  The primary key in a database consists  of  a  unique  identifier  for  a  particular record and should only point to a single record in the database being indexed. Secondary  key—  Data  are  normally  arranged within   a   database   in   some   type^- of   order, depending  upon  the  contents  of  one  or  more fields. Secondary keys allow you to access the database  in  different  ways.  For  example,  your database  might  be  arranged  in  the  order  the records  were  entered.  You  can  then  set  up  a secondary index (or key) by the name field, or by the  social  security  number  field.  You  may specify  any  number  of  secondary  keys.  You might   index   by   more   than   one   field.   For example, you could index by last name within rate, as shown in figure 3-6. Database  Organization  Methods/Structures Databases can be  list,  hierarchical,  network,  or relational  in  structure. The  major  advantage  of  a 3-12