Strings are bytes (numbers), which are mapped to characters

'PAULO ROMA' = 0b1010000 0b1000001 0b1010101 0b1001100 0b1001111 0b100000 0b1010010 0b1001111 0b1001101 0b1000001
= 80 65 85 76 79 32 82 79 77 65
= 0x50 0x41 0x55 0x4c 0x4f 0x20 0x52 0x4f 0x4d 0x41
ASCII table

32 = 33 = ! 34 = " 35 = # 36 = $ 37 = % 38 = & 39 = '
40 = ( 41 = ) 42 = * 43 = + 44 = , 45 = - 46 = . 47 = /
48 = 0 49 = 1 50 = 2 51 = 3 52 = 4 53 = 5 54 = 6 55 = 7
56 = 8 57 = 9 58 = : 59 = ; 60 = < 61 = = 62 = > 63 = ?
64 = @ 65 = A 66 = B 67 = C 68 = D 69 = E 70 = F 71 = G
72 = H 73 = I 74 = J 75 = K 76 = L 77 = M 78 = N 79 = O
80 = P 81 = Q 82 = R 83 = S 84 = T 85 = U 86 = V 87 = W
88 = X 89 = Y 90 = Z 91 = [ 92 = \ 93 = ] 94 = ^ 95 = _
96 = ` 97 = a 98 = b 99 = c 100 = d 101 = e 102 = f 103 = g
104 = h 105 = i 106 = j 107 = k 108 = l 109 = m 110 = n 111 = o
112 = p 113 = q 114 = r 115 = s 116 = t 117 = u 118 = v 119 = w
120 = x 121 = y 122 = z 123 = { 124 = | 125 = } 126 = ~ 127 = 

Computers use binary numbers, but people need a more friendly number system

Dictionaries associate keys to values (any object):

Dictionaries can be sorted either by key or by value: