# Effective Kotlin Item 54: Prefer Sequences for big collections with more than one processing step

DevFeed: [Effective Kotlin Item 54: Prefer Sequences for big collections with more than one processing step](<https://devfeed.tech/articles/effective-kotlin-item-54-prefer-sequences-for-big-collections-with-more-than-one-processing-step-39290.md>)

Original publisher: [Read original article](<https://kt.academy/article/ek-sequence>)

Published: 2021-09-20T00:00:00Z

Content type: tutorial

Language: en

Sources: [Kt. Academy](<https://devfeed.tech/sources/kt-academy.md>)

Topics: [Sequences](<https://devfeed.tech/topics/sequences.md>), [Collections](<https://devfeed.tech/topics/collections.md>), [.NET](<https://devfeed.tech/topics/net.md>)

Tags: [collections](<https://devfeed.tech/tags/collections.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [lazy](<https://devfeed.tech/tags/lazy.md>), [order-of-operations](<https://devfeed.tech/tags/order-of-operations.md>), [sequences](<https://devfeed.tech/tags/sequences.md>), [workshop-learning-programming](<https://devfeed.tech/tags/workshop-learning-programming.md>)

## AI overview

This article explains the difference between Kotlin collection and sequence processing. Sequences are lazy: intermediate operations build a processing chain, and calculations occur during terminal operations. The article discusses their element-by-element ordering, reduced processing work, support for infinite sequences, and avoidance of intermediate collections.

## Source excerpt

What the difference between list and sequence processing is, and when each should be preferred.