If you are using a windows-based device, yes, you need an annual based licensed antivirus.
If you are using an Apple device, you do not need any antivirus software. But you do need an adware or spyware blocker.
An Antivirus solution is best installed right after your computer has been formatted. It acts as a security guard. It takes a snapshot the files that are already inside your system and then it keeps a lookout for strange behavior caused during installations and captures the process and infecting file source and quarantines it, where it can do no more harm. So ideally when your computer gets infected, if you install an antivirus solution after that, it will not make much difference. It needs to be formatted first. As soon as a computer is formatted, Antivirus needs to be installed right away, failure to do so will leave the device open to threats and viral infection. If you have decided to backup content before formatting, all backups and USB drives need to be scanned for viruses and threats so as not to re-infect the system by copying the data content once more.Antivirus software should not consume excessive memory. Antivirus should not be intrusive, and it must not disturb the user.
Provide proper ventilation to your Laptops to avoid overheating & hanging problems. Do not put on laptops Laptop keeping of fabric or bed because generally, the air circulation is from the base, regular doing so may reduce the life of the laptop, and can occur the heating problems
Always keep your Laptops dust free for the long life of your Laptops. Smart tune-up and clean-up junk files will help your Laptops for better performance. Keep your laptop free from Spywares and Adware's use a proper antivirus software to protect your privacy & data.
Do not subject your laptop to shocks and jerks. It may avoid destruction to your hard disk drive. Ideally, power the laptops off before moving it from one place to another place.
Use strong passwords (Ex: ABC$123#abc) for your all your online accounts to avoid hacking and phishing.
Preventative maintenance: periodic checks on your laptop before problems occur to avoid downtime of your systems.
If you're not using the laptop for a long time, then remove the battery power from the laptop. To extend the battery life span, to save the power use Standby and hibernation options. The best practice is to maintain long battery life is to charge and discharge.
Don't consume or drinking near or around your laptop. The least bit of water could short-circuit some delicate laptop tour and provide it ineffective.
Desktops are much cheaper than a laptop, and its parts are also less expensive and easy to replace. So, Desktops are cost-effective and easy in repairing. Desktop components are more performing. Overall long hour of working experience on a desktop is much better than on a laptop. Desktop is the best choice for long hour office work and kids' education.
Laptops are very portable due to their compact size. Laptops can have a reasonably wide variety of component options, but they are more limited than desktops. To get a more powerful laptop (higher speed, better graphics, more storage space, etc.), the price can be considerably higher. The main attraction of a laptop is its portability features. You can move with all your data, OS and application software to make your work much more comfortable than desktop.