Difference between High Level Design(HLD) and Low Level Design(LLD)

System design involves creating both a High-Level Design (HLD), which is like a roadmap showing the overall plan, and a Low-Level Design (LLD), which is a detailed guide for programmers on how to build each part. It ensures a well-organized and smoothly functioning project. High-Level Design and Low-Level Design are the two main aspects of System Design.

What is High Level Design(HLD)?

High-level design or HLD refers to the overall system, a design that consists description of the system architecture and design and is a generic system design that includes:

1. System architecture
2. Database design
3. Brief description of systems, services, platforms, and relationships among modules.

A diagram representing each design aspect is included in the HLD (which is based on business requirements and anticipated results).

• It contains description of hardware, software interfaces, and also user interfaces.
• It is also known as macro level/system design
• It is created by solution architect.
• The workflow of the user’s typical process is detailed in the HLD, along with performance specifications.

What is Low Level Design(LLD)?

LLD, or Low-Level Design, is a phase in the software development process where detailed system components and their interactions are specified.

• It describes detailed description of each and every module means it includes actual logic for every system component and it goes deep into each modules specification.
• It is also known as micro level/detailed design.
• It is created by designers and developers.
• It involves converting the high-level design into a more detailed blueprint, addressing specific algorithms, data structures, and interfaces.
• LLD serves as a guide for developers during coding, ensuring the accurate and efficient implementation of the system’s functionality.

Differences between High Level Design(HLD) and Low Level Design(LLD): 

Conclusion

High-Level Design documents are like big-picture plans that help project managers and architects understand how a system will work and low-Level Design documents are more detailed and are made for programmers.

• They show exactly how to write the code and make the different parts of the system fit together. Both documents are important for different people involved in making and maintaining the software. 
• Creating a High-Level Design is like making a big plan for the software, and it helps find problems early, so the quality of the software can be better assured.
• On the other hand, when Low-Level Design is well-documented, it makes it easier for others to check the code and ensure its quality during the actual writing of the software.

Both these steps help catch and fix issues early, making the overall software development process smoother and more reliable.