Virus is a word of Latin origin, whose meaning is poison or toxin. It is a biological entity that has the ability to self-replicate using cellular machinery.
A virus is made up of a protein capsid that surrounds nucleic acid (DNA or RNA). This structure, in turn, may be surrounded by the viral envelope (a lipid layer with different proteins).
Specifically, we can establish that, by classifying viruses, we can form two large groups. Thus, we would have, on the one hand, the so-called DNA viruses that identify themselves by the fact that they take as their stage of development what is the nucleus of the cell in question. Within this category, there are, in turn, two classes: single-stranded, in which single-stranded DNA takes center stage, and double-stranded, which, in your case, has double-stranded DNA. On the other hand, we find RNA viruses, so called because they use RNA (ribonucleic acid) as genetic material and also take the cytoplasm as a place to replicate. Within this modality there are four groups: the positive single strand, the reverse transcribed single strand, the double strand and the negative single strand. The life cycle of the virus, a potentially pathogenic agent, requires the metabolic machinery of the invaded cell in order to replicate its genetic material and produce many copies of the original virus. This process can damage the cell to the point of destroying it. This operation has been imitated by so-called computer viruses, which are programs that are automatically copied and whose purpose is to affect the normal functioning of a computer, without the user’s consent. In the strict sense of the term, computer viruses are programs that can be replicated and run on their own. In their actions, they tend to replace executable files on the system with others infected with malicious code. Viruses can simply annoy the user, block networks generating useless traffic, or directly destroy data stored on the computer’s hard drive. When it comes to talking about computer viruses, we must mention the most famous or most frequent among which, for example, Trojan horses. They are those that can be defined as those that steal information, allow an external user to control the computer or simply change said device. However, we must also talk about those known as worms, whose main hallmark is that they hide and reproduce on their own. And all this without forgetting the so-called time bombs, which are those viruses that activate on a certain date or simply when a certain function is performed.
There are two main distinctions between the classes of viruses. On the one hand, there are viruses that infect files: these, in turn, are divided into direct-acting viruses (the infection occurs when they are executed) and resident viruses (they lodge in the computer’s memory and infect other programs like them). are accessed). On the other hand, boot or boot sector viruses appear.