Transistors are the fundamental and necessary parts of any electronic gadget. They consist of 3 main parts: Base, collector, and emitter, and simply have 2 main functions: Amplifying the electric signals and switching the circuits on and off. Transistors are excellent tools for amplification, voltage stabilization, signal modulation, switching, and so on. It is also good to note that the first transistor was developed and introduced in 1947 at Bell Laboratories.
Secondly, I would consider e-mail as another IT solution that played a vital role in recent history. As there is no letter, paper, or something else to write on required and all the communication is over the internet, there is added an "e" (means electronic) before the word mail. The first e-mail would be considered the one sent on an application called MailBox at the computers of MIT in 1965. Later, Arpanet's e-mail system was developed by Ray Tomlinson in 1971. Speed, convenience, constancy are some primary reasons why e-mails are always one of the most preferable means of communication.
Lastly, the DNS also can be considered as an IT solution in the contemporary world. In order to simplify the networking, especially accessing websites, Paul Mockapetris began working and introduced the first DNS - Domain Name System in 1985. Until then people needed to remember and enter the IP addresses for accessing anything on the web. However, thanks to the creation of DNS, it became much easier to access anything on the internet, since only entering the names - the website names started being required. Later, To prevent the DNS servers from DNS poison attacks, DNSSEC - DNS Security Extensions were developed.
To conclude all, the aforementioned IT solutions and many more made our lives and surfing on the web easier.
