Library

/ ˈlaɪ.brer.i /

Definition

Software engineers write lots of code. However, engineers don’t want to re-invent the wheel. They make their lives easier by using a collection of code someone else already wrote. 

This collection of code is called a library. Engineers can plug-and-play libraries wherever they see fit. Libraries can be made available to the public where anyone can use and individually improve them (aka open-source software). They save a ton of time for engineers and is often considered more reliable than coding from scratch because other engineers have already battle-tested and implemented it for their own projects. Ordering pizza instead of cooking on your own is less time spent in the kitchen and more time given back to you.

Used in a sentence

Example 1: product manager wants a new featureProduct Manager: How hard would it be to develop this feature? Lead Dev: There might be a library for it so it may not take long at all.

Example 2: sometimes libraries have vulnerabilities tooDev 1: I just read the news on the log4j library. Can we make sure our code isn't using it?Dev 2: Yeah, our code uses it in a couple spots. I'll make sure to remove it.

Related terms

• Open Source

• Modules

• Packages

• Dependencies

• Software Development Kit (SDK)