A bodyguard protects the person. In Australia bodyguards may be armed, or unarmed, depending on the circumstances. The environment is generally low risk; risk can be heightened by political activism, being a member of a distinct target group, being a high profile member of the entertainment industry, or a myriad of other more personal reasons. Kidnap and ransom are not common in Australia, however, they are common in some sub-groups, and definitely in parts of Asia, Africa, and South America.

Some clients have insurance that requires them to have bodyguards, not matter the level of risk the environment presents (kidnap and ransom insurance).

Kidnapping for financial gain, especially in South America and Africa, is about money, money is about power. The kidnappers have the leverage of holding hostages. They intend to obtain the maximum financial reward from these assets. They know they hold the power over the hostage's family or business colleagues, generally.
To maximise this leverage the criminals know they need to prey on emotional responses. To do this they will use images of cruelty and torture, emotional phone calls, and calls where the hostage is being tortured, allowing you to hear what is happening. The best defence to this is to maintain an emotional balance, to keep logic in play.
Both sides are aware that a ransom will be paid. On a business level the hostage takers are attempting to gain the maximum return. Any initial offer will be turned down, as not big enough. The hostage will generally be tortured to determine the assets and wealth of the family. This will be used against you.
Tell the hostage they have your love and support at every opportunity. Engage negotiators. You are looking for Crises negotiators for kidnap and ransom (K & R).
When conducting handovers, and collection of hostages, this becomes another area of negotiation.  Attempt to avoid entering an unstable country, unless there are particulars advantages.
e.g. Somalia lies beside Kenya, which by the local standards is a stable democratic country. Do your handovers in Kenya. Mexico lies near Nicaragua, Honduras and El Salvador (be mindful of local 'no go' zones, and the politics of different countries).
Armed rescue. Despite what you see in the movie's armed rescue is not, generally, an option. A negotiated outcome is. In most area's private groups will lack the local knowledge, intelligence, expertise and finances to mount an effective operation.  Anything other than a lightning fast, targeted, professional assault before any resistance can be mounted is doomed to failure.
Action by government forces in many countries will result in the death of both hostage takers and hostages, or at the very least a set back in negotiations as the criminals will be unsure if you have been straight with them.
Negotiation is not complete until the hostages have been recovered and removed to a safe place. Considerations include valid passports, visa's, medical support, the condition of the hostage both physical and mental, method of transport. This must be part of contingency planning.
Ransom negotiations are usually conducted in US dollars, some are moving to gold, some are moving to crypto currencies.
We are no longer involved in the provision of bodyguards, as the field has become flooded with returned serviceman.