Used as a base in most electronics and their boards called Printed Circuit Board (PCBs).Used for the specific purpose of a wiring area for surface-mounted and socketed components and for a physical support piece and is mainly made from common fiber-glass, composite epoxies or another form of composite material in each company’s own PCB Design Services

The types of electronics dictates the type of PCBs used. For example, multiple layered has, sometimes up to twelve layers and are used in your high and more sophisticated hardware found in computers as graphic cards and motherboards whereas your single-layered boards are for the more simple electronics like calculators, etc.

Even though most people think of PCBs as associated only with computers and such and actually realizing that the smaller electronic devices and which many seem to think as simple can have those multilayered PCBs as well, but not all as per all dictated by their usage, technological advances, and users. Devices such as radios, TVs, digital cameras, video cameras, cell phones, tablets and notebooks/laptops. These are considered consumer usage PCB devices

Where we also find them and in many other varieties and fields with examples being:

Medical devices: as these devices become denser and less power consuming it became absolutely perfect and essential for many important and vital life saving medical devices and medical technologies. The medical field uses mostly High-Density PCB devices as this creates the smallest and densest to be used e.g. pacemakers and hearing aids. In some of the medical technology fields, these devices with the PCBs have found their way into from the smallest as mentioned, before, to the biggest like CAT scans and MRI machines to the precision robotic operating arms used in the most delicate of theatre procedures like brain and other neurosurgery’s.

Other devices also using these PCB Design Services worth mentioning are:
Industrial machinery, Lighting, and the Automotive and aerospace industries

As mentioned before we have single and multilayered PCBs but theses can even be divided further into types of layers all depending on their usages and theses examples are as follows:
Double-layer PCBs
Rigid PCBs
Flexible PCBs
Rigid-Flex PCBs
High-frequency PCBs
Aluminum-backed PCBs.(this one having extra advantages specifically such as • Low cost. • Environmentally friendly. • Heat dissipation. • Material durability. Much High-frequency PCBs and PC connector types have many things to be considered when designing and choosing the right boards such as:
Dielectric loss (DF)
Thermal expansion
Water absorption
Other resistances