Why are my queries in idle state?

I’m new to postgres , I’ve aws rds instance running postgresql with engine version 11.5.

All my queries are clientRead has the wait_event. Why do I have all my queries in idle status.Does this mean they are idle in transaction?

What are the steps should I take to fix this?

If I change to idle_in_transaction_session_timeout to 10 mins for example will it fix this?

select count(*),state FROM pg_stat_activity group by 2;
 count | state
-------+--------
     5 |
     1 | active
   451 | idle


Select pid, datname, usename, wait_event_type, wait_event, backend_type FROM pg_stat_activity where state='idle';
  pid  | datname  |         usename          | wait_event_type | wait_event |  backend_type
-------+----------+--------------------------+-----------------+------------+----------------
 14797 | xxxxx    | user                     | Client          | ClientRead | client backend


SELECT current_setting('idle_in_transaction_session_timeout');
 current_setting
-----------------
 1d
(1 row)