das Echo
echo
The reverberation of sound that occurs when sound waves are reflected back from a surface and you hear the sound again.
In der großen Halle gab es ein beeindruckendes Echo.
There was an impressive echo in the large hall.

echo
Loading your saved state.
echo
The reverberation of sound that occurs when sound waves are reflected back from a surface and you hear the sound again.
In der großen Halle gab es ein beeindruckendes Echo.
There was an impressive echo in the large hall.

In the literal sense, 'Echo' (echo) is often used with verbs such as 'hören' (to hear) or 'geben' (to produce/give). People speak of an echo 'in den Bergen' (in the mountains), 'in einem Tunnel' (in a tunnel), or 'in einer leeren Halle' (in an empty hall).
Als wir in die Höhle riefen, hörten wir ein lautes Echo.
When we called into the cave, we heard a loud echo.
You can recognize the figurative meaning 'Reaktion' (reaction/response) from the context. Typical signal words are 'Presse' (press), 'Medien' (media), 'Kritiker' (critics), or 'Publikum' (audience). This is not about sound, but about opinions and feedback.
Die Rede des Politikers löste ein geteiltes Echo in den Medien aus.
The politician's speech triggered a mixed response in the media.
In the figurative sense, 'Echo' (response) is often combined with adjectives such as 'positiv' (positive), 'negativ' (negative), 'breit' (broad/widespread), or 'schwach' (weak). Common verbs are 'finden' (to find/receive), 'bekommen' (to get), 'erhalten' (to receive), or 'auslösen' (to trigger).
Sein Vorschlag fand bei den Kollegen ein positives Echo.
His proposal received a positive response from his colleagues.
A common fixed expression is 'auf Echo stoßen' (to meet with a response). It means that an idea, proposal, or action evokes a reaction.
Ihre Initiative ist bei der Bevölkerung auf ein positives Echo gestoßen.
Her initiative met with a positive response among the public.
reaction
'die Reaktion' and 'das Echo' can both mean how people respond to something or react to it. 'die Reaktion' is the more general word and fits a single response, behavior, or statement. 'das Echo' is used more when talking about the effect of a statement, action, or idea on a group or in the public sphere. It often sounds like collective feedback. For a personal response, you usually say 'Reaktion'. For the response to a speech, a project, or an article, 'Echo' often fits well.

Der neue Vorschlag bekam im Team ein positives Echo.
The new proposal received a positive response from the team.
Seine Reaktion auf die schlechte Nachricht war sehr ruhig.
His reaction to the bad news was very calm.