HLD vs LLD

LLD vs HLD

HLD and LLD

HLD & LLD are 2 terms used commonly used in Network Design, Operation and implementation.

Full-Form of HLD –

HLD stands for High Level Design

What is HLD?

HLD or high level design is created initially during the Design journey of a Solution. It provides a high-level view of overall System setup describing the relationship of various systems and functions which combine to provide the expected solution.

Full-Form of LLD –

LLD is an abbreviation for Low Level Design.

What is LLD?

LLD is created on the footsteps of HLD and provides detailed and in-depth information of the HLD. Some terms related to HLD include Zoning, Traffic flow and high-level connectivity across various elements of the solution, while LLD is more related to terms like VLAN, IP address, port numbering etc.

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Below table summarizes the differnce between HLD and LLD:

PARAMETER	HLD	LLD
Abbreviation For	High Level Design	Low Level Design
Philosophy	Overall Network Design describing relationship between various system modules and functions.	Detailed design depicting in depth information of the HLD.
Translation	Converts Business Requirement into High Level Solution.	Converts High Level Solution to Detailed Solution.
Chronological order in design phase	Created 1st in chronological order.	Created after HLD has been designed and agreed.
Related terms	Zones, Traffic flows, high level connectivity across various entities.	VLAN, Port numbering, configuration settings etc.
Created By	Solution Architect	Designer
Target Audience	Used for management, Program and solution teams.	Used for Designers, Operation Teams and Implementers.
Expected Outcome	Required to understand flow across various system entities.	Is input for creating configurations and troubleshooting.