What is the difference between a signal peptide and a transit peptide?
Signal peptides are typically located at the N terminus of a protein. The signal peptides are processed by the translocon machinery and are cleaved off after sorting through the membranes of organelles in the secretory system:


  
  endoplasmic reticulum
  Golgi apparatus 
  ER-Golgi transition vesicles 
  plasma membrane
  lysosomes
  


Transit peptides target the protein to other subcellular organelles such as (from UniProt):


  
  Mitochondrion
  Apicoplast
  Chromoplast
  Chloroplast
  Cyanelle
  Thylakoid
  Amyloplast
  Peroxisome
  Glyoxysome
  Hydrogenosome
  


N-terminal transit peptides are quite rare. C-terminal transit peptide motifs are much more common. UniProt holds transit peptides as a discrete controlled vocabulary, separate from signal peptides.