These are quite general terms that may be used in several contexts and may have slightly different meanings depending on that context.
Client and server is a pair that usually only exists in combination. A client requests some information from the server and the server delivers that information. Although the opposite direction (client provides information to the server) is also possible the roles are fixed by the used protocol. To be reachable by the clients the server must have a well-known IP-address (given that we talk about IP-network client/server pairs), in most cases this address must be fixed.
A station is not a generally defined term. Every context that use that term should define it's meaning first. Usually it's a participant in some kind of network, other terms for the same often used are "node" and "host".
An access point usually describes a network device that provides WiFi service for some area in Managed mode. In most home setups it's part of the functionalities the internet router offers.
The SSID identifies a single WiFi network. It's simply a name and may be shared by several access points or routers if you have a bigger network.
An access point is by definition not coercively a server but as in the home situation the router (which is the access point) in most cases contains a web server it is also a server but it doesn't have to for it's functionality as an access point, it just makes the configuration convenient.