I want to digitize automatically old paper map that scanned to jpg . I know that it's possible to digitize it with arc-map but I can not remember how to do it.
It sounds you are after automatic raster to vector conversion and the extension to ArcGIS for Desktop that does that (as mentioned in a comment by @radouxju) is ArcScan:
ArcScan provides tools that allow you to convert scanned images into vector-based feature layers. The process of converting raster data to vector features is known as vectorization. Vectorization can be performed manually by interactively tracing raster cells or automatically using the automatic mode.
I've lost track of how licensing for ArcScan works but this GeoNet thread answered by an Esri staff member suggests that that at ArcGIS 10.1 it became included with all license levels.
Scan the map to xxx format and add the map to ArcGIS (sounds like you have it in jpg already).
Use the Georeferecning Tools to get the map in the correct location using ancillary data. A good time to set the projection.
Create empty point, line, and polygon Feature Classes.
Using the Editing Toolbar to digitize your features into the files
Add required attributes.