die Eröffnung
opening
The act of making a shop, exhibition, or public institution accessible to the public for the first time.
Zur Eröffnung des neuen Museums kamen tausende Besucher.
Thousands of visitors came to the opening of the new museum.

opening
Loading your saved state.
opening
The act of making a shop, exhibition, or public institution accessible to the public for the first time.
Zur Eröffnung des neuen Museums kamen tausende Besucher.
Thousands of visitors came to the opening of the new museum.

'Die Eröffnung' (the opening) is the nominalization of the verb 'eröffnen' (to open). This formation with the ending '-ung' is very common in German for turning a verb into a feminine noun.
Wir planen, das neue Café im Mai zu eröffnen.
We are planning to open the new café in May.
To say what is being opened, you often use the genitive or the preposition 'von' (of/by). In written language, the genitive is common, for example 'die Eröffnung des Festivals' (the opening of the festival).
Die Eröffnung des neuen Flughafens wurde verschoben.
The opening of the new airport was postponed.
In this meaning, 'Eröffnung' is often combined with adjectives like 'feierlich' (ceremonial) or 'groß' (grand). Typical nouns are 'Geschäft' (shop), 'Ausstellung' (exhibition), or 'Filiale' (branch).
Die feierliche Eröffnung des neuen Theaters zog viele Prominente an.
The ceremonial opening of the new theater attracted many celebrities.
When 'Eröffnung' means the beginning of an event, it is often used in connection with 'Konferenz' (conference), 'Sitzung' (meeting/session), or 'Veranstaltung' (event). A person then often gives an 'Eröffnungsrede' (opening speech).
Die Eröffnung der Konferenz übernimmt der Rektor der Universität.
The rector of the university will take over the opening of the conference.
In a legal context, 'Eröffnung' is a fixed term. People speak of the 'Eröffnung eines Insolvenzverfahrens' (opening of insolvency proceedings) or the 'Eröffnung eines Testaments' (opening of a will).
Das Gericht hat die Eröffnung des Verfahrens beschlossen.
The court decided to open the proceedings.
In chess, 'die Eröffnung' refers to an established sequence of the first moves of a game. These openings often have names, such as 'die Sizilianische Eröffnung' (the Sicilian Opening).
Ein guter Schachspieler kennt viele verschiedene Eröffnungen.
A good chess player knows many different openings.
end
'das Ende' and 'die Eröffnung' form a contrast in the context of events, businesses, or official procedures. 'die Eröffnung' is the beginning: something is started or made accessible for the first time. 'das Ende' is the close: after that, the event or procedure is over. 'Eröffnung' often sounds a bit more official than simply 'Anfang' (beginning), especially for exhibitions, businesses, or proceedings.

Zur Eröffnung der neuen Bibliothek hält die Bürgermeisterin eine kurze Rede.
At the opening of the new library, the mayor gives a short speech.
Vor dem Ende des Konzerts gingen einige Besucher schon nach draußen.
Before the end of the concert, some visitors had already gone outside.