A balun is an electrical device that converts between a balanced signal (two signals working against each other where ground is irrelevant) and an unbalanced signal (a single signal working against ground or pseudo-ground). A balun can take many forms and may include devices that also transform impedances but need not do so. Transformer baluns can also be used to connect lines of differing impedance. The origin of the word balun is balance + unbalance.

Generally a balun consists of two wires (primary and secondary) and a toroid co it converts the electrical energy of the primary wire into a magnetic field. Depending on how the secondary wire is done the magnetic field is converted back to a electric field.

A Choke - is simply a piece of coax or wire which is wound at the mininum bend radius of the coax. Several turns of coax makes a simple choke.
You have to be very careful not to open up the shield by winding it too tightly.

Baluns can take many forms and their presence is not always obvious. Sometimes, in the case of transformer baluns, they use magnetic coupling but need not do so. COMMON MODE CHOKES ARE ALSO USED AS BALUNS! and work by eliminating, rather than ignoring, common mode signals.

The key word there is - used as baluns.
If it was a Balun - they would call it a Balun

Coax works on the principal of a Faraday Cage.

Maybe you would like to explain for the people on this forum what a Faraday Cage is?