Salesforce REST API call into Force.com platform requires OAuth 2.0 authentication. OAuth is an industry-standard authentication mechanism using "tokens" instead of a typical "username" and "password" credentials. OAuth access tokens provide permission to make Salesforce API calls, and do not grant permission to login to Salesforce Web UI.
1. Navigate to Connected App on Salesforce UI.
Setup -> Build -> Create -> Apps -> New Connected Apps.
