The marking of resistors is applied to its case in the form of different letters, numbers, signs and colored rings. Among the many ways to get the most distribution is the color marking of the resistors. It is applied most often in the form of 4 colored rings; rarely 5 rings. The first two or three digits of the number of the number (mantis), the third (or quarter) ring is a multiplier. The last color bar by how many percent the true value may deviate from the claimed value.
Marking of resistors of type MTL of the Soviet manufacture represents figures and letters. For example, 110R changes 110 ohms, 18k - 18k ohm, 1k8 and k18 - 1800 and 180 ohm respectively, 1M - 1MΩ and so on.
Marking SMD resistors is applied in the form of three digits: the first two digits - the value of the number (mantis), the third number - the multiplier. For example, 111, 181, 180, 182 are 110, 180, 18 and 1800 ohms respectively, 183 to 18 kilohms, 105 to 1 ohm, and so on. This marking is also used for capacitors, only there the initial value are picofarads.
SMD components greatly simplified the automatic process of mounting parts on the board, which allows to speed up the manufacture of devices and its weight and dimensions, as well as the final cost of the electronic device.
However, the most reliable way to know the value of a resistor or other radioelectronic element is to check its value with a multimeter or other measuring device.
When measuring resistance, you should always follow a simple rule - do not touch your fingers with the fingers of the resistor terminals and the measuring probes of the multimeter. Otherwise, everything will be an error in the measurements, because the human body has its resistance and will shunt the resistor.