Money is clearly a primary need of every human being that cannot be avoided, human needs can be realized by using money. Seeing from the lack of systematic literature review papers discussing cryptocurrency, this is a challenge as well as the main purpose of this paper. Along with the development of modernization and globalization which has now entered the industrial era 4.0 revolution there is a blockchain based technology, Cryptocurrency. Cryptocurrency is one of the developments of the blockchain that is often used as a decentralized digital currency. The word Cryptocurrency means a virtual currency that has no physical form, and Cryptocurrency also means that the transaction currency cannot be seen and is safe. This digital currency has many types such as Bitcoin, Ethereum, Litecoin, Monero, and many other types. Although it has no physical form, this currency functions the same as conventional currencies in general and has an exchange rate. Exchange rates on Cryptocurrency fluctuate which means unexpected, this is often exploited by traders. Cryptocurrency transactions in the form of forwarding from one individual to another individual online, therefore they deal directly without a third party. Every technology has advantages and disadvantages aside from efficiency and convenience, Cryptocurrency has the disadvantage of not having the authority responsible for dealing with all problems that occur in all transactions, and money laundering crimes also often occur, this is a challenge for how to utilize Cryptocurrency and blockchain technology in the current era of globalization.

The services of skilled construction workers are only known around them in the sense that they are not yet widespread in the community, therefore an application is needed that can help construction workers services and can make it easier for the wider community to find construction workers services. The purpose of this research is to build applications as building laborer services based on android and to make construction workers able to compete in this era of industrial revolution 4.0. The method used in this research is the waterfall methodology, where in this methodology each stage of the research is carried out sequentially, starting from the stages of analysis, design, writing program code, testing, and maintenance. This application uses Adobe Illustrator, AirDroid, Android Studio and Sublime Text, but the problem in this research is that it is very difficult to find experienced and professional construction workers and most of these construction workers do not understand the digital world so it is difficult to develop this research in old school community (do not understand the world of technology today).

With the advancement of information technology has grown so rapidly. One form of development that can be seen in the existence of a platform that connects one another or what can be said is social media. Instagram, Facebook, Twitter and Tiktok are examples of social media that are the most popular platforms. Starting from children to adults all use social media[1]. With this, social media has become a concern for business people. Now, almost all business people do not hesitate to market their products or services through social media. On that basis, this article was written. The goal is to see how digital marketing is useful in today's business strategy.

With the rise of world progress, information technology and telecommunications to the Internet have become a top priority. These advancements mark a watershed moment in mobile learning, or "mobile learning," as it is known (m-learning). M Learning has some extra learning capacity that can be accessed by anybody, at any time, from anywhere. The issues still exist in m-learning, including a shortage of hardware and platforms required by the system architecture and accessibility. In order to become comfortable for the user, a thorough examination of each component dealing with existing m-learning is also required. This research aims to address the problem by employing multimedia as a material that can provide more precise and detailed information. Multimedia m-learning services necessitate an internet connection, excellent access, and adequate hardware to benefit from the overall bias with good services provided by phones that offer mobile multimedia facilities. The study's primary goal is to create m-learning with multimedia services, and the expected results are a software-based content provider.

With the advancement of information technology has grown so rapidly. One form of development that can be seen in the existence of a platform that connects one another or what can be said is social media. Instagram, Facebook, Twitter and Tiktok are examples of social media that are the most popular platforms. Starting from children to adults all use social media[1]. With this, social media has become a concern for business people. Now, almost all business people do not hesitate to market their products or services through social media. On that basis, this article was written. The goal is to see how digital marketing is useful in today's business strategy.