What does 103 mean on an SMD resistor?

10 followed by 3 zeros: 10 × 10³ = 10,000 Ω = 10 kΩ.

What does the R mean, like in 4R7?

The R is the decimal point, so 4R7 = 4.7 Ω and R47 = 0.47 Ω.

A 3-character code where two digits look up a value in the E96 table and a letter gives the multiplier, e.g. 01C = 100 × 100 = 10 kΩ.

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SMD code

3-digit: first two digits are significant, the third is the multiplier (number of zeros). 103 = 10 × 10³ = 10 kΩ.
4-digit: first three significant, last is the multiplier. 1002 = 100 × 10² = 10 kΩ.
R notation: the letter R marks a decimal point. 4R7 = 4.7 Ω, R47 = 0.47 Ω.
EIA-96: two digits look up a value from the E96 table, and a letter gives the multiplier. 01C = 100 × 100 = 10 kΩ.

EIA letter	Multiplier	EIA letter	Multiplier
Z	0.001	B / H	10
Y / R	0.01	C	100
X / S	0.1	D	1000
A	1	E	10000
		F	100000

What does 103 mean on an SMD resistor?: 10 followed by 3 zeros: 10 × 10³ = 10,000 Ω = 10 kΩ.
What does the R mean, like in 4R7?: The R is the decimal point, so 4R7 = 4.7 Ω and R47 = 0.47 Ω.
What is an EIA-96 code?: A 3-character code where two digits look up a value in the E96 table and a letter gives the multiplier, e.g. 01C = 100 × 100 = 10 kΩ.