The Europa League and Europa Conference League group stages gets under way on Thursday with several Premier League and Scottish Premiership sides involved.

Brighton, Liverpool and West Ham and Rangers all involved in the Europa League, while Aston Villa and Aberdeen take part in the Europa Conference League this season.

BBC Sport takes a look at the key things to watch out for.

Brighton heading into the unknown

There will be six teams making their Europa League debut this season, with Brighton one of them.

The Seagulls continue to look impressive under Roberto De Zerbi and, just like they did in the Premier League last season, they will be confident of causing a few upsets as they make their debut in Europe.

They are in Group B along with Dutch giants Ajax, French side Marseille and AEK Athens from Greece.

"[Our opponents] are all good teams, but we are a good team too," said De Zerbi.

"It's the first time for Brighton in Europe. You can imagine the passion there will be to get points and qualify. We want to win the group. It is not important which club we have to play."

Liverpool make Europa League return

The last time Liverpool featured in the Europa League they reached the final - losing 3-1 to Sevilla in 2016.

That was Jurgen Klopp's first season at the club and the German has gone on to win the Champions League, Premier League, FA Cup, League Cup and Uefa Super Cup since then.

The Reds are in Group E with Austrians LASK, Union SG of Belgium and French side Toulouse.

"I've never played against one of the teams, which I love, and I'm really excited about it," Klopp said.

"When I saw it I went through the squads directly and tried to figure out a little bit who I know, what I know already, but that's obviously not enough at the moment.

"We will be prepared."

Hammers becoming European veterans

European trips are becoming the norm for West Ham fans these days.

This will be their third consecutive season in Europe. They reached the semi-finals of the Europa League in 2021-22, when they were knocked out by Eintracht Frankfurt, and then beat Fiorentina last season thanks to a late Jarrod Bowen goal to win the Europa Conference League.

The Hammers will have to navigate through a pretty tough-looking Group A that features Greek side Olympiakos, Germans Freiburg and Serbians TSC.

"To be a European winner is something really special," said West Ham boss David Moyes.

"The night was magical for us and for us to score in the last minute makes it even better."

Rangers return

Like West Ham, Rangers are back in the Europa League for the first time since 2021-22, having last year competed in the Champions League.

They failed to get out of the group stage on that occasion and were then thrashed 7-3 on aggregate in qualifying for Europe's elite club competition this time round.

That meant they dropped into the Europa League group stage, where they will face Spanish side Real Betis, Czechs Sparta Prague and Aris Limassol of Cyprus in Group C.

Villa back in Europe after 13 years

Aston Villa are back in Europe for the first time since the 2010-11 season, when they competed in the Europa League.

Unai Emery's side finished seventh in the Premier League to give them a shot at competing in the Europa Conference League, and they cemented their place in the group stage of the competition by thrashing Hibernian 8-0 on aggregate.

They kick off their campaign against Polish side Legia Warsaw, and also face Dutch team AZ Alkmaar and Bosnian side Zrinjski Mostar.

Tough test for the Dons

Aberdeen, meanwhile, have a tough test in Group G as they have been draw against Eintracht Frankfurt, who defeated Rangers on penalties in the 2022 Europa League final.

Finnish champions HJK Helsinki and Greek side PAOK are also in their group.

The Dons enter the competition at the group stage after losing their Europa League play-off to BK Hacken.

What are the key fixture dates?

Europa League Group stage:

Matchday one: 21 September

Matchday two: 5 October

Matchday three: 26 October

Matchday four: 9 November

Matchday five: 30 November

Matchday six: 14 December

Knockout round play-offs: 15 and 22 February 2024

Round of 16: 7 and 14 March 2024

Quarter-finals: 11 and 18 April 2024

Semi-finals: 2 and 9 May 2024

Final: 22 May 2024

Europa Conference League group stage:

Matchday one: 21 September

Matchday two: 5 October

Matchday three: 26 October

Matchday four: 9 November

Matchday five: 30 November

Matchday six: 14 December

Knockout out round play-offs: 15 & 22 February

Round of 16: 7 and 14 March

Quarter-finals: 11 and 18 April

Semi-finals: 2 and 9 May

Final: 29 May

Where are the Europa League and Europa Conference League finals?

The Europa League final will take place at the Dublin Arena in the Republic of Ireland on 22 May 2024, while the Europa Conference League final is at AEK stadium in Greece on 29 May 2024.