LinkedIn is based on a network of contacts, each user has his own network, and within each one there are connections of different degrees, let’s see what each of them means.
First degree connections.
In this type of contacts are all those users that you have directly in your network, i.e. those that you have asked for a connection or that have asked you for a connection.
The publications of these people are the ones that will appear on the wall of the social network when you enter it and they will also be the first to see your publications.
You will know that someone is a first degree connection because you will see a 1st next to their name.
Second degree connections.
Those users who are connections of your first degree contacts. That is, they are direct contacts of your own contacts.
You will know that someone is a second degree connection because you will see a 2nd next to their name. You will be able to connect with them to become a first-degree connection or send them messages via inMail.
Third degree connections.
In this case, these are the people connected to your second-degree connections, i.e. contacts of contacts of contacts of contacts.
Remember that LinkedIn is like a network and so, even though this is not a first contact, there will be a better chance of them getting to know you than someone who is not in your network because they are not a contact for any of your connections.
You will know that someone is a second degree connection because you will see a 3rd next to their name.
You will be able to connect with them to become a first-degree connection or send them messages via inMail.