Electronics is a branch of physics that deals with behavior and controlled flow of electrons in vaccums and gases, and with the use of electron tubes,transistors etc..; Electronics had the distinction from electrical technology with the invention of triode on 1906. Triode was used for electrical amplication with a non-mechanical device. Now a days most of the electronic devices are made from semiconductors to control electron flow in the devices.
Have you ever seen inside FM radio box ? Can you identify components present inside that box ? So many small components are there. We know that voltage commonly used in our home appliances is 110-230V (It varies for each country). After plugging the wire from FM radio into socket and turning the switch on, FM radio functions. 230V is applied between the terminals of primary coil of transformer. A tranformer has the capability to change high voltage to low voltage (step up transformers) and vice versa (step down transformers).
It converts 230 V into low level voltage. If you traverse after transformer, you will encounter the components which are small in size and operating on low voltage.
If you explore inside your computer, you will find many rectangular shape objects which have many vertical pins along edges.They are known as IC (integrated circuits) chip that consists of many electronic components together.