<h1 id="heading-what-is-the-difference-between-stationery-and-non-stationary-data">What is the difference between stationery and non-stationary data?</h1>
<h2 id="heading-stationary">Stationary:</h2>
<p><strong>A series is said to be "STRICTLY STATIONARY” if the Mean, Variance &amp; Covariance is constant over some time or time-invariant.</strong></p>
<p><img src="https://cdn.hashnode.com/res/hashnode/image/upload/v1675186624155/0b22af3d-9ec4-4b52-844b-ec7c5a3e47d9.png" alt class="image--center mx-auto" /></p>
<h2 id="heading-non-stationary">Non-Stationary:</h2>
<p><strong>A series is said to be "STRICTLY STATIONARY” if the Mean, Variance &amp; Covariance is not constant over some time or are time-invariant.</strong></p>
<p><img src="https://cdn.hashnode.com/res/hashnode/image/upload/v1675186634927/a8311b79-5e19-458b-9b62-cfb70312742c.png" alt class="image--center mx-auto" /></p>


# What is the difference between stationery and non-stationary data?

## Stationary:

**A series is said to be "STRICTLY STATIONARY” if the Mean, Variance & Covariance is constant over some time or time-invariant.**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1675186624155/0b22af3d-9ec4-4b52-844b-ec7c5a3e47d9.png align="center")

## Non-Stationary:

**A series is said to be "STRICTLY STATIONARY” if the Mean, Variance & Covariance is not constant over some time or are time-invariant.**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1675186634927/a8311b79-5e19-458b-9b62-cfb70312742c.png align="center")

What is the difference between stationery and non-stationary data?

#92 Machine Learning & Data Science Challenge 92

Stationary:

Non-Stationary:

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#92 Machine Learning & Data Science Challenge 92

Table of contents

What is the difference between stationery and non-stationary data?

Stationary:

Non-Stationary: