You will encounter the right of signature both when you want to have a joint account with another person, whom you will allow to dispose of the account, and when you need to make a legal transaction but you are on vacation. You may also come across it in the case of entrepreneurs who appoint someone as a proxy and authorise them to perform legal acts in the operation of the business.
Special power of attorney to sign the contract
Are you going on a holiday or business trip, for example, and you know that while you are away you need to take a legal action (such as signing documents) that only you can do? To avoid having to come back for this, you can give someone you trust a special power of attorney authorising them to do this for you under a power of attorney.

When you say proxy
Even a businessman does not have to act for his company all the time, personally. He can also delegate another person to perform certain legal acts on his behalf. In this case, we speak of proxy, which is based on the Civil Code. It is actually a special kind of power of attorney that authorises the proxy to perform legal acts that occur in the operation of the business.
A proxy may be a natural person who is legally capable of performing legal acts. It may be an employee or another person who is not in an employment relationship with the entrepreneur. A proxy is created by a written agreement which clearly states that it is a proxy.