What do these 2 functions do? Please go into detail, thank you

int writeSock(int sock, char* buf, size_t len) { ssize_t byteswrote = 0; ssize_t ret = 0;

while (byteswrote < len) { ret = send(sock, buf + byteswrote, len - byteswrote, 0);

if (ret < 0) { return -1; }

if (ret == 0) { break; }

byteswrote += ret; }

return byteswrote; }

int readSock(int sock, char* buf, size_t len) { ssize_t ret = 0; ssize_t bytesread = 0;

while (bytesread < len) { ret = recv(sock, buf + bytesread, len - bytesread, 0);

if (ret == 0) { break; }

if (ret < 0) { return -1; }

bytesread += ret; }

return bytesread; }