If you want high performance, the CPU uses a lot of electricity. The TDP of a powerful desktop computer can range from 450 to 850 watts, or more. That's why high-performance computers use a standard wall plug. They also generate a lot of heat, often requiring large heat sinks (passive cooling), or fans or liquid cooling (active). whereas, the mobiles...Smartphones and tablets run on batteries, which means they have to use power as efficiently as possible. It's not feasible to provide high, constant power to a device's CPU from such a small battery. Consequently, the newest smartphone will not give you as much power as a high-end desktop computer. Mobile devices are getting more powerful every month, but traditional computers always have the performance edge, due to consistent access to more electricity.
In terms of cost prices for a computer can vary widely depending on its capabilities, storage, and features. A mid-range computer usually costs between $500 and $800, and some of that cost can be offset if you already own peripherals, such as a monitor, keyboard, and mouse. More powerful computers will cost between $1000 and $2000, or more again The price of a smartphone can be financed month-to-month as part of a service plan from providers, such as Verizon or AT&T. Refurbished smartphones can be purchased on an e-commerce site like eBay or Amazon for $100-$300. However, new flagship smartphones can cost as much as $1300. Tablets, depending on size, usually cost between $200 and $600.
With the size of desktop computers, they can connect to a wide variety of monitors, allowing you to invest as much or as little as you want into that component. Most modern computer monitors are LCDs. Depending on their size, quality, and features, they generally cost between $100 and $500 (although some can cost much more).
Smartphone screens vary somewhat depending on the manufacturer and model. However, they always be smaller than a desktop or laptop as they generally range between four and seven inches.
Desktop computers generally come with Ethernet capability, either on the motherboard or a discrete NIC. Most desktop computers require a peripheral device, such as a USB Wi-Fi adapter, to connect to wireless networks. Most laptops include both Wi-Fi and Ethernet networking as a standard feature. Smartphones and tablets can connect to Wi-Fi networks for Internet access. Also, smartphones can connect to a mobile data network; many tablets offer mobile data connectivity as well. Mobile data, however, comes at a premium and can be much more expensive than a standard broadband connection.
In my opinion mobiles are more portable and thus more comfortable to carry arround.
