Information
The following information was summarised from various sources for your convenience.
C is the third letter in the Latin alphabet. Later use When the Roman alphabet was introduced into Britain, c represented only /k/ and this value of the letter has been retained in loanwords to all the insular Celtic languages: in Welsh, Irish, Gaelic, c represents only /k/. In addition, Norman used the Greek letter k so that the sound /k/ could be represented by either k or c the latter of which could represent either /k/ or /ts/ depending on whether it preceded a front vowel or not. In these cases, the Old English c gave place to k qu ch but, on the other hand, c in its new value of /ts/ came in largely in French words like processiun, emperice, grace, and was also substituted for ts in a few Old English words, as miltse, bletsien, in early Middle English milce, blecien. In the orthographies of English, French, Spanish and Portuguese, c represents the "soft" value before e or i and a "hard" value of /k/ elsewhere. Other language orthographies use c to represent other sounds
There are several common digraphs with c, the most common being ch, which in some languages such as German is far more common than c alone.