In short, a rectifier is a device that converts AC to DC, and diodes are usually part of its implementation.
In DC power supplies, you commonly find rectification done by 4 diodes in a full-wave-bridge configuration. Some rectifiers are more than simple diodes, like SCRs (silicon controlled rectifier) which have a control leg and are used for switching rather than just AC to DC conversion. In fact, one big application of silicon controlled rectifiers is to make AC from DC, how confusing is that!
Diode is a general class of 2-terminal semiconductors, and there are all kinds of diodes whose primary purpose is not rectification of AC: LEDs, photodiodes, lasers, zeners for voltage regulation, etc. Before semiconductors were invented, diodes were vacuum tubes.
Diode refers to a device with two electrodes. Examples are semiconductor diode, vacuum tube diode, etc.
Rectifier is an electrical device that allows electrical current to flow in only one direction and current is blocked in the reverse direction. Rectifier may have additional electrode such as the gate in SCR (silicon controlled rectifier). In the early days of ham radio, people use copper oxide and selenium rectifier in their equipment.
A rectifier is a type of diode. A rectifier is intended to handle higher currents or voltages.
Signal diode is made for low voltages and currents. The dividing line is kind of vague.
Other type of diodes: zener, tunnel, schottky, LED, varicap, photodiode, SCR, tunnel, laser, PIN, and more
A rectifier is a device that can change AC into DC. A diode is the name of a component which can be used as a rectifier. Most people would generally use these terms interchangeably as the most common usage of a diode is to perform rectification. But technically the term rectifier can cover a larger group of components and circuits which convert AC to DC of which a Diode can function as a member of this group. Consider a commutator as a mechanical device that rectifies the AC in the armature of generator into pulsating DC. You would not call a commutator a diode, but you could call a commutator a rectifier.
Diode is a semiconductor device it can be used to rectify the voltage.
Diode can be used as a rectifier rectifier is a circuit used to convert AC to Dc voltage for rectifing AC to DC diodes,scr,triac etc devices can be used.