Handling IC / OOC conversations and meta-communication
I've played in-person for more than forty years and online for nearly six. The biggest difference I have noticed is in terms of handling in character vs. out-of-character discussions, and compartmentalizing information between players. Simply put, it is far easier to 'whisper' between players and between a player and the DM online, so players may react more strongly to evidence that secret information is being shared in person. It is also easier online to have clear boundaries about when a player actually commits to their character's action. This might or might not be an issue - it largely depends on your playgroup and the style they are accustomed to.
'Hey Gwen, I'm at 2hp over here - could I get a heal?'
Some groups treat the 'six second combat round' to mean players must make decisions about their character's actions in a limited amount of time and with limited input from the other players.
Other groups feel free to discuss tactics and plan moves for half an hour before anything actually happens in-game. If, as a DM, you prefer the 'no table-talk / no kibitzing during combat' style, you might think you are enforcing this online, when your players are actually 'whispering' or talking over other channels to one another. Collaboration will be more obvious in person, meaning if you are trying to prevent this you will have to choose how to prevent it, and what to do when the players push back.
'Dorja tells the King to go **** himself' jk
Similarly, each table has its own social contract about what counts as a statement of character intent. Some groups allow only In Character statements, and follow 'if you said it, you did it' protocols. Others are comfortable with the DM saying, "Are you sure that's your action?" after they have insulted NPC's and then said they were Out Of Character joking, or after they have suggested an action and then had fellow players remind them of why that would be a bad idea. If you have players that continually hedge about what their characters are actually doing, it is harder to pin them down at a table. Online you can implement rules like, "If it is in the chat, you did it" and go back and read the record like a court stenographer. In person you may get attempts to say, "I didn't really mean that," or "That's not what I actually said."
DM: 'The Countess enters the room and smiles winningly at each of you, although her eyes linger a half-second longer on Sir Tristan."
Players A, B, C, and D [unconcerned]: 'We bow and wait for her to speak.'
[DM hands Player B a note; Player B makes a roll and shows it to just the DM; Players A, C, and D look at each other, alarmed]
Player A: 'My bard starts to play a counter-charm'
Player C: 'I cast Detect Magic'
Player D: 'I cast Bless on A, C, and myself.'
Online servers are great for handling secret information between players, and between a player and a DM. In-person, communicating in secret is much more obvious - and can result in players using that meta-information in the game. You may have decisions to make about how to handle this.