Is there a way to allow more power to USB Devices powered by the Pi I have a model B+, and I am unable to power my Webcam plugged into the Pi it has a single USB Connection so there's no way to power it from another medium
The Pi requires 5V power to run. The power supplies of the Pi have an Amperage rating. ie RPi3 recommends using 3A, which contributes to the power of the Pi, and subsequently any USB devices connected to the Pi's USB ports. They will feed off this USB Power line...
The Pi draws power from this line, and in itself, the more components utilized the more power it will be drawing..
i.e. running Wifi, Bluetooth, Ethernet will all take from this Amperage.
I like to use the analogy of the Water pipes in the house. Voltage is like the diameter size of the pipe, where as Amperage is like the water pressure applied to that pipe. In order to take a proper shower, you need the pipe to be a certain size (Pi:5V), and with enough pressure (Pi:2-3A) coming though, the shower functions properly. When you get more members of the house taking showers at the same time (i.e. more USB devices plugged in), the overall pressure drops. If that pressure drops low enough, it will no longer allow the household guests to properly take their showers. This is where you start to see components fail on the Pi, or the Pi itself crashes.
There are different methods to powering the Pi (and it's power parasite USB peripherals)...
Aside from reserving the Pi's power supply for Pi use alone, You can implement a Powered USB Hub as mentioned. This will have it's own separate power supply, and typically provides anywhere from 3-4 Amps to the USB Hub peripherals alone.
You can certainly plug the Raspberry Pi straight into this hub and use the hub's power to operate the RPi.
Another solution I've tried recently was obtaining a double-ended USB Type-A cable, plug one end into another wall plug USB brick phone charger, and the other end into a spare USB slot on the RPi... This will parallel the Amperage between the two supplies, contributing to the Pi's existing power bus line, adding more amperage.
One side note: You can actually power the RPi this way without using the small micro-USB power port on the Pi, using the dual ended Type A cable, from power brick to the Pi's USB ports: BUT THIS IS NOT RECOMMENDED! As the power is regulated/protected coming in the micro-USB, and the Pi's USB power line is not.
The USB Hub method is a good method, but adds a bulky hub, Power supply to the equation... The dual ended USB Type-A approach at least eliminates the hub part, but doesn't provide extra USB ports, but takes up one on the Pi.