> For the complete documentation index, see [llms.txt](https://blog.telegram.lvivcenter.org/tg-research/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://blog.telegram.lvivcenter.org/tg-research/filters/filters-basics.md).

# Basic Information about Filters

{% embed url="<https://app.guideflow.com/player/qp7z276sjk>" fullWidth="true" %}

Before we move on to filters, we suggest you familiarize yourself with the main features of working with them:

* A system of logical operators `OR` and `AND` is applied in each filter. By default, the `AND` operator is in effect, combining all selected search queries. For example, with the filters "Country" > "Ukraine" `AND` "Poland" enabled, the results will display messages that mention both countries. By changing the operator from `AND` to `OR` in the lower right corner of the filter, the results will display messages that mention one `or` more countries.

<div data-full-width="true"><figure><img src="/files/wHewto6hW2E07LDEpKsU" alt=""><figcaption></figcaption></figure></div>

* All selected filters are displayed at the top of the search results. This allows you to see which filters are active and easily disable them.

<div data-full-width="true"><figure><img src="/files/3dtYUNmJaD6dVujqBXjD" alt=""><figcaption></figcaption></figure> <figure><img src="/files/7UoMgQKS8nSLwcywg4E5" alt=""><figcaption></figcaption></figure></div>

* Next to each item in the filter panel, the number of messages corresponding to that item is displayed. For example, this could be the number of messages with a specific hashtag or those published by a particular author. These numeric indicators may change if the search parameters are adjusted.

<figure><img src="/files/qnZ6HOnuY3M57MRJQyCP" alt="" width="375"><figcaption></figcaption></figure>

* Since the list in some filters can be too long, each has a <img src="/files/sTsdcKrWa1HE5PfQpCg2" alt="" data-size="line"> button. You can view the entire list using this button and find the items you need by name. The display order can be sorted alphabetically (the<img src="/files/EYaZuN17FyXDX1xj8hkQ" alt="" data-size="line">button) or by the number of messages (the<img src="/files/dVv8HJlwmFcSJVfwm0Rn" alt="" data-size="line">button).

<figure><img src="/files/twe4wR6krQ8EQthQegsl" alt="" width="375"><figcaption></figcaption></figure>