Depending on the API you call, you will get back one or more 'records'. The format of the record that you get back is controlled by a parameter in the request called 'ResourceType'. The Infoconnect API supports 5 predefined resource types, and also supports a 'custom' resource type that allows for a more à la carte selection of output fields for each record. Common to the /people, /companies and /match APIs are 3 record types: Core, Basic, and Enhanced. The /people and /match API also includes 2 additional types: TargetReady, and LifeStyle.

Core
The most basic record is the 'Core' record. It contains just the Id of the record.
Basic
The basic resource type includes everything in the 'Core' type, plus adds other fields like address and geo-location (lat/long).
Enhanced
The enhanced resource type builds on the basic type and adds additional fields. The actual fields you get back depend on the API you are calling.
LifeStyle
The LifeStyle information indicates an individuals interest in different habits and behaviors.
TargetReady
The TargetReady information predicts whether a household is likely to be interested in different things.

In addition to each of these predefined record types, the Company object and the Person object define a number of fields that are not included in the predefined records. You may not need all the fields in an Enhanced record, you might only be interested in a particular data point. Using the 'Fields' option in the search criteria, you can specify the exact list of fields you want to have returned. For example, when the following is included with the search input for the /companies API:

{"Fields":["Address", "CompanyName", "CorporateEmployeesSizeActual", "County", "ProductsSold" ]}


Only those fields will be included in each record in the output:

[
	{
	    "ETag": "73b66919",
	    "Id": "826381212",
	    "Links": [
	        {
	            "Href": "/v1/companies/826381212",
	            "Rel": "self"
	        },
	        {
	            "Href": "/v1/companies/637824467",
	            "Rel": "parent"
	        }
	    ],
	    "Address": "1020 E 1st St",
	    "CompanyName": "Infogroup Inc",
	    "CorporateEmployeesSizeActual": 1900,
	    "County": "Sarpy",
	    "ParentCompany": "637824467",
	    "ProductsSold": "SALESGENIE, REFERENCEUSA.COM, CREDIT.NET, INFOUSA.COM, EXPRESSUPDATEUSA.COM, INFOCONNECT, TARGET READY MODELS, ISELL, YESMAIL ENTERPRISE, MARKETZONE GOLD, MARKETZONE PLATINUM, B2B DATA, B2C DATA"
	}
]