How count polygons (buildings in area) without information loss

[VeryTary]

Hi, I'm pretty new with GIS and ArcGIS, so sorry for my not fully appropriate technical language.

Have two features:

1) different areas = big polygons, in violet color

2) buildings inside area = smaller polygons, pink color

I need to count how many buildings are into each area. I wanted to use this (count overlapping polygon):
https://www.arcgis.com/home/item.html?id=1dd4a6832b3d40b494dbf8521cc5134c 

but I need to ''merge'' (?) the features into one, keeping the different polygons (I've tried different commands, and sometimes they merge features but also polygons, so I lost my buildings in a nutshell).

How can I solve?

Thank you

[DanPatterson_Retired]

Spatial join might work to get the attributes together, then a Summarize to get the count

[MervynLotter]

If you are only interested in the count, you could convert your buildings

to a point feature and then run spatial join to get the number of points

within your polygons.