The anticodon region of a transfer RNA is a sequence of three bases that are complementary to a codon in the messenger RNA. During translation , the bases of the anticodon form complementary base pairs witht the bases of the codon by forming the appropriate hydrogen bonds.
In this diagram you see a tRNA that has the anticodon UUU which is complementary to the codon AAA. The codon AAA specifies the amino acid phenylalanine.
You also see the tRNA with the anticodon CCC which is complementary to the codon GGG. The codon GGG specifies the amino acid glycine.
The amino acid phenylalanine is always covalently bonded to the tRNA with the anticodon UUU or UUC because these two codons specify the amino acid phenylalanine. The amio acid glycine is covalently bonded to tRNAs with the anticodons GGU, GGA, GGG or GGC because these three codons specifiy the amino acid glycine.