Do postgres use implicit transaction in UPDATE ... RETURNING queries?

Can someone let me know if Postgres 15 uses implicit transactions for
UPDATE...RETURNING queries?

For example, is there any differences between the two queries

BEGIN;UPDATE counterSET value = value + 1
RETURNING value;COMMIT;

and

UPDATE counterSET value = value + 1
RETURNING value;

Table is like below

CREATE TABLE IF NOT EXISTS counter
(
value bigint PRIMARY KEY NOT NULL DEFAULT 0,
updated_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP
);