A Glossary of Key Terms in Database & API-Specific Delta for HR & Recruiting
In today’s fast-paced HR and recruiting landscape, leveraging automation and seamless data flow is no longer a luxury but a necessity. Understanding the foundational concepts of databases and APIs, particularly how they handle “delta” changes, empowers HR leaders and recruiting professionals to optimize their tech stacks, streamline workflows, and ensure data integrity. This glossary defines key terms, explaining their practical application in enhancing talent acquisition, HR operations, and overall business efficiency.
API (Application Programming Interface)
An API acts as a messenger, allowing different software applications to communicate and share data. For HR and recruiting professionals, APIs are the backbone of integration, enabling systems like an Applicant Tracking System (ATS), Human Resources Information System (HRIS), payroll software, or background check platforms to exchange information automatically. Instead of manual data entry, an API allows your ATS to send candidate details directly to your HRIS upon hire, or to trigger a background check instantly. Understanding how APIs work is crucial for building interconnected HR tech ecosystems that reduce manual effort and accelerate processes, transforming disparate tools into a cohesive operational unit.
Database
A database is an organized collection of structured information, or data, typically stored electronically in a computer system. For HR and recruiting, databases are fundamental. Your ATS stores candidate profiles, resumes, interview notes, and job application histories within a database. Your HRIS houses employee records, compensation details, performance reviews, and benefits information. Effective database management ensures that this critical data is accurate, accessible, and secure. Leveraging well-structured databases allows for robust reporting, efficient candidate searching, and reliable decision-making, directly impacting talent management and operational efficiency within your organization.
Delta (Data Delta / Delta Sync)
In data management, a “delta” refers to the change or difference between two versions of data. A delta sync is the process of synchronizing only the data that has changed or been newly added, rather than transferring an entire dataset. For HR and recruiting automation, delta sync is incredibly powerful. Instead of pushing all 50,000 candidate records from your ATS to your CRM every night, a delta sync might only transfer the 50 new applicants or 10 updated profiles. This significantly reduces processing time, bandwidth usage, and resource strain, ensuring that your systems remain updated with the most current information while operating efficiently and minimizing the risk of data redundancy.
Webhook
A webhook is an automated message sent from one application to another when a specific event occurs, essentially an “event-driven” notification system. Think of it as a reverse API call. In HR and recruiting, webhooks are pivotal for real-time automation. When a new candidate applies in your ATS, a webhook can instantly notify the hiring manager via Slack, trigger an automated email sequence to the candidate, or initiate a new workflow in your onboarding system when an offer is accepted. Webhooks enable instantaneous reactions to critical events, eliminating delays and manual triggers, thereby accelerating your recruitment funnel and employee lifecycle processes.
JSON (JavaScript Object Notation)
JSON is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It’s the most common format for data exchange between web servers and web applications, especially with REST APIs. For HR and recruiting, when you integrate systems like an ATS with an HRIS, the candidate or employee data (e.g., name, email, skills, job title) is frequently transmitted as JSON. Understanding JSON, even at a high level, helps HR professionals grasp how data is structured when moved between systems, facilitating smoother data mapping and troubleshooting during automation setup and integrations.
XML (Extensible Markup Language)
XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. While JSON has largely overtaken XML for new web services due to its simpler syntax, XML is still prevalent in many legacy systems and specific industry standards, particularly for data feeds. In HR and recruiting, you might encounter XML when parsing older job board feeds, integrating with certain enterprise HR systems, or exchanging data with specific third-party vendors. Recognizing XML helps in understanding and integrating with a broader range of HR tech, ensuring compatibility across diverse platforms.
REST API (Representational State Transfer API)
REST API is an architectural style for designing networked applications. It defines a set of constraints for how data should be retrieved and manipulated, primarily over HTTP. It’s the most common and flexible type of API used today for web services. Most modern HR platforms – ATS, HRIS, CRM, payroll, and benefits systems – expose REST APIs. This allows for robust and standardized integrations. For HR and recruiting automation, using REST APIs means your Make.com or Zapier workflows can reliably send and receive candidate, employee, or job data, enabling complex cross-system automations that are scalable and maintainable.
GraphQL
GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. Unlike REST, where clients typically receive a fixed data structure from an endpoint, GraphQL allows clients to request exactly the data they need, and nothing more. This precision can be incredibly beneficial in HR and recruiting, especially for complex dashboards or analytics where you only need specific fields from multiple related data points (e.g., candidate name, application date, and specific skill score, but not their entire resume). GraphQL can optimize data fetching, reduce over-fetching, and improve the performance of data-intensive HR applications.
SQL (Structured Query Language)
SQL is a powerful programming language designed for managing and manipulating data stored in relational databases. Many HR and recruiting systems, especially enterprise-level HRIS and ATS solutions, rely on SQL databases. While HR professionals typically won’t write SQL queries daily, understanding its role is important for advanced reporting, data extraction, and custom analytics. If you need a very specific report on employee tenure combined with performance ratings, or a list of candidates from a particular source with specific keywords, SQL is the language used under the hood to pull that precise information from the database, enabling deep insights into your workforce data.
NoSQL Database
NoSQL (Not Only SQL) databases are non-relational databases that provide a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. They are particularly good for handling large volumes of unstructured or semi-structured data. In an HR context, NoSQL databases might be used for storing diverse candidate profiles (with varying fields), social media data, detailed resume parsed data, or large logs of communication and interaction histories. Their flexibility makes them ideal for modern HR tech that deals with dynamic data models and rapidly evolving data needs, offering scalability beyond traditional relational structures.
Data Migration
Data migration is the process of transferring data between computer storage types, formats, or systems. This is a common and critical task in HR and recruiting, often occurring during major system overhauls. Examples include moving all candidate data from an outdated ATS to a new, modern platform, or consolidating employee records from multiple regional HR systems into a single global HRIS. Successful data migration requires careful planning, data cleansing, transformation, and validation to ensure data integrity and minimize disruption. Executed well, it ensures continuity and accuracy of essential HR information in new operational environments.
ETL (Extract, Transform, Load)
ETL is a three-step process used to integrate data from disparate sources into a single repository, such as a data warehouse or a new operational system.
Extract: Data is pulled from various source systems (e.g., different job boards, internal spreadsheets, HRIS).
Transform: The extracted data is cleaned, standardized, de-duplicated, and validated to ensure consistency and quality (e.g., ensuring all date formats are the same, parsing full names into first/last).
Load: The transformed data is then loaded into the target system.
In HR, ETL is vital for building comprehensive analytics dashboards, migrating complex datasets during system upgrades, or consolidating candidate pipelines from multiple sources into a unified view for recruiters, ensuring data is always clean and actionable.
Data Integrity
Data integrity refers to the overall completeness, accuracy, and consistency of data throughout its entire lifecycle. Maintaining high data integrity in HR and recruiting is paramount because inaccuracies can lead to significant problems. Imagine incorrect compensation data leading to payroll errors, duplicate candidate profiles wasting recruiter time, or missing certifications causing compliance issues. Automation, especially with delta syncs and robust ETL processes, plays a crucial role in preserving data integrity by reducing manual entry errors, ensuring consistent data formats, and regularly validating information across integrated systems, ultimately building trust in your HR data.
Authentication
Authentication is the process of verifying the identity of a user, system, or application trying to access a resource. It ensures that only authorized entities can perform certain actions or access sensitive data. In HR and recruiting, strong authentication is critical for protecting highly confidential candidate and employee information. When your ATS connects to a background check service via an API, both systems must authenticate each other to confirm they are legitimate and authorized to exchange data. Proper authentication, often involving API keys, OAuth tokens, or other security protocols, is a cornerstone of data security and regulatory compliance in all HR automation.
Endpoint
An endpoint, in the context of APIs, is a specific URL or URI (Uniform Resource Identifier) where an API can be accessed. It’s the precise location on a server that represents a particular resource or function. For example, in an ATS API, `/candidates` might be an endpoint to retrieve a list of all candidates, while `/candidates/{id}` might be an endpoint to retrieve details for a specific candidate. Understanding endpoints helps HR professionals and integrators identify exactly where to send data requests or to receive data from when setting up automation workflows, ensuring data is exchanged with the correct part of the target system.
If you would like to read more, we recommend this article: CRM Data Protection & Business Continuity for Keap/HighLevel HR & Recruiting Firms
