The metro system of Berlin (S-Bahn) has two kinds of trains. The oldest lines have narrower trains called Kleinprofilzüge (small profile trains) and the newer lines have broader trains. This train in the picture no.496/497 is from the type A3-64, built by Orenstein & Koppel in 1964. It's one of the narrower trains and currently one of the oldest trains in use, athough there is still another A3 train type subtype A3-60 which is even older, dating back to 1960. At least in theory there are still 50 trains of this type still in use. It's a two-coach unit, 2,3 meters wide and with a top speed of 62 km/h. Like all of the Berlin S-Bahn trains it runs with 750 V DC from a side rail.
Picture from Nollendorfplatz in Berlin 25.11.2023 by Matti Heino.

This is a side view of a Berlin U-Bahn train of the type A3L92. These trains were essentially the last batch of earlier type A3 trains, but now built from aluminium to save weight and thereby electricity by accelerations. This last series A3L92 from the year 1992 differs from the earlier A3 trains only by its light grey inner walls. The earlier ones had dark walls inside. These were quickly built after the German reunification and thereby the reunification of the Berlin metro system to get rid of old and unreliable East German metro train models.
Picture from the metro station of Dahlem Dorf 1.9.2022 by Ilkka Siissalo.

Inside view of a Typ A3L92 metro train.
Picture from near the metro station of Dahlem Dorf 1.9.2022 by Ilkka Siissalo.

A proper outside view of the Berlin metro type A3L92. Picture from the station Krumme Lanke 13.10.2004 by Wikipedia user "Jcornelius".
Published under the CC BY-SA 3.0 license

Metro train no.605 which is another one of the type A3L92 trains is here just stopping at the Augsburger Strasse U-Bahn station.
Picture 10.11.2006 by Ilkka Siissalo.

BVB no.615 is yet another one of the type A3L92 trains. Here we see it approaching the Möckernbrücke station.
Picture from Berlin Möckernbrücke 5.3.2016 by Ilkka Siissalo.

The same BVB no.615 as seen above, just stopping at the Möckernbrücke station.
Picture from Berlin Möckernbrücke 5.3.2016 by Ilkka Siissalo.

Old one goes, a new one arrives. An A3L92 train distances itself and at the same time a new train no. 1020 arrives.
Picture from Berlin Möckernbrücke 5.3.2016 by Ilkka Siissalo.

A new train reflects the rails in front. This no.1020 was built by Bombardier in 2007. It belongs to the new class of S-Bahn trains HK06.
Picture from Berlin Möckernbrücke 5.3.2016 by Ilkka Siissalo.

This Berlin metro train 2749 belongs to the type F84 and it was built by Waggon Union in 1984.
Picture from the metro station of Westphalweg 10.11.2006 by Ilkka Siissalo.

This Berlin metro train 2887 is somewhat newer. It belongs to the series called F90. F90 trains consist of only two coaches and just one end has a driver's cab (so called half-trains), so they always need to be used as pairs of two coaches each. They were built in the year 1990 by what then was ABB (Asea-Brown Boweri).
Picture from the station Möckernbrücke 5.3.2016 by Ilkka Siissalo.

Outside view of a newer Berlin metro train of the type H97.
Picture 12.5.2006 by Ilkka Siissalo.

BVB metro train no.1081 is a former East German train, which is here totally modernised and rebuilt. It was actualy twice modernised and rebuilt, first in 1992 and then also in 2007. It was originally built by LEW in East Germany in 1988. It now belongs to the so called GI/1E class.
Picture from Möckernbrücke 5.3.2016 by Ilkka Siissalo.

Here the same no. 1081 as above is approaching Möckernbrücke station.
Picture from Möckernbrücke 5.3.2016 by Ilkka Siissalo.

Another former East German metro train, now number 1092 shown in a closeup. This one also is of the class GI/1E, originally built by LEW in 1988-89 and modernised in 1992 and again in 2009.
Picture from Möckernbrücke 5.3.2016 by Ilkka Siissalo.

Coaches of the same former East German metro train no.1092 shown above.
Picture from Möckernbrücke 5.3.2016 by Ilkka Siissalo.

BVB S-Bahn train no.5001 is the very first one of the class H95 (later H96-H97) trains. It is a fixed set of 6 coaches forming like a single "tube" for the passengers. It was built by ABB in 1994.
Picture from the Alexanderplatz station 20.4.2017 by Ilkka Siissalo.

These are currently the oldest metro trains of the city of München. This is the so called U-Bahn type A, which is a two-coach EMU unit. Max three of these two-coach pairs can be coupled to form a metro train. They were built 1970-1984 and there are/were 147 pairs in total. One pair has 98 seats. They have a power rating of 720 kW and a maximum speed of 80 km/h.
Picture from the Dietlindenstrasse U-Bahn station 14.10.2022 by Ilkka Siissalo.

Another "Typ A" metro train, one with a bit more fresh painting.
Picture from the Hauptbahnhof U-Bahn station 14.10.2022 by Ilkka Siissalo.

Inside view of one of the old "Typ A" metro trains.
Picture 14.10.2022 by Ilkka Siissalo.

This is the so far newest metro train type of München, the so called Typ C2. They have been in use since 2016. It consists of six coaches which are permanently fixed together so that inside it looks like a single long tube. Its maximum speed is 90 km/h, but only 80 km/h is used in operational use. The train is 115 metres long and it has 220 seats.
Picture 14.10.2022 from the station Dietlindenstrasse by Ilkka Siissalo.

Inside view of a Typ C2 metro train.
Picture 15.10.2022 by Ilkka Siissalo.

This is the type C metro train of München. Types C and C2 are almost identical and the C2 is an improved version of this type C. C2 has stronger motors so that it can accelerate even better. From the outside they are easy to distinguish from each other due to very different front lights.
Picture from the station Sendlinger Tor 12.10.2022 by Ilkka Siissalo.