What is the BIOS? What is the UEFI?

In what ways are they different?

What is the BIOS? Could you explain it? What about the UEFI? They are not the names of two comic brothers, but two softwares that coexist in our computers and allow them to boot and run to carry out tasks as important as working, communicating with our loved ones, exchanging memes or even watching videos of little cute kittens and puppies.

At this point, and after accompanying us for so many years in countless bootings, it is likely that at least the BIOS of a computer rings a bell. However, and although their functions are very similar, the UEFI is a complete stranger for many people.

In this article, we are going to take a look at this pair of “sisters” who have the specific feature of being essential for our computers and being exclusive in the near future, at least in the case of the UEFI, since it has started to replace the BIOS in modern computers. But first, let us get to know better what the BIOS is.

What is the BIOS?

What is the BIOS? It is the accronym of “Basic Input Output System”, a software that is installed by default in the motherboard of a PC (there are also those who identify it as the chip that hosts it, due to its firmware nature) and whose function is allowing the computer to boot, before the operating system starts working.

The BIOS is hosted inside an integrated circuit and is supported by another chip called CMOS, which acts as a kind of memory that is used by the BIOS. What the BIOS does is, basically, executing a series of routines that enable verifying the state of the computer and its startup. Thus, right after the computer has been booted, the BIOS is responsible for starting, configuring and testing the hardware of the computer, to subsequently start the boot manager that will allow the startup of the operating system. Its function, therefore, is twofold: on the one hand, it boots and verifies the state of the hardware and on the other hand, it works as a kind of “bridge” that allows the hardware and the operating system to begin to “understand each other”.

Up to now, we could suppose that, although its function is very important, the BIOS could go more or less unnoticed. What happens is that, sometimes, we are very aware that the BIOS is there, fulfilling its function, and it is usually at the worst moments: when problems arise.

Indeed, if while carrying out any of its tasks, the BIOS detects any error, it will not allow the system to continue booting until the failure is solved. Sometimes, it could even get to the point of warning us about something that does not work properly through its famous and shrill beeps, which might be different depending on the type of error found. This is the cumbersome moment that we have all experienced at some point, when the BIOS tells us something is wrong and we are forced to get into its menus to fix the problem (if we are able to do so).

However, the BIOS is not only available when things go wrong. Even if there are no issues, we can always access the BIOS menus to make changes to the configuration of the computer (something that is only advisable to carry out if we really know what we are doing).

What happens with the BIOS is that, although it has been doing its job well for decades, times change, and from time to time younger creations that surpass the old ones are born. And that leads us to UEFI.

What is the UEFI?

So we have just answered the question “what is the BIOS?”, but what is the UEFI? The accronym UEFI corresponds to the term “Unified Extensible Firmware Interface”.

UEFI is an improvement or evolution of the BIOS. Its functions are basically the same, to which it adds greater security, speed and compatibility with modern devices. In addition, UEFI is capable of supporting hard drives that exceed 2.2 Tb, which is a limitation for the BIOS, since it cannot boot them.

Currently, UEFI is present in most of the computers manufactured in recent years, sharing functions with the BIOS in some cases and having completely replaced it in some others.

UEFI was developed in the 90s by Intel, and it has become a standard in motherboards, due to advantages such as its faster startup speed and an interface that offers more possibilities to the user than those provided by the classic BIOS.

So, at this point we can say that UEFI has come to the motherboard market to give a well deserved retirement to our beloved BIOS, which has been with us for more than 30 years and was already in need of a break, do you not think so?

And now, a little bit of monitoring

And now that we have found out the answers to the questions “what is the BIOS?” and “what is the UEFI?”, what about spending a few minutes to get to know a monitoring tool like Pandora FMS?

Pandora FMS is a flexible monitoring software, capable of monitoring devices, infrastructures, applications, services and business processes.

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Or you can also send us any questions you may have about Pandora FMS.

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