In Redhat Linux such as CentOS and RHEL, OpenSSL package provides three categories of functions
libcrypto: This category include generic encryption related functions. The generic functions provided by libcrypto are used by other programms such as Bind,SASL, OpenSSH etc.
libssl: This category provides open source implementation of TLS and SSL. As we know there are many programs that use TLS/SSL such as OpenLDAP,Apache etc.
OpenSSL utilities: This category includes multi purpose command utilities to generate keys,csr,certificates,encrypted data etc. openssl command is very powerful and can many cryptography tasks.
OpenSSL provides cryptography functions through libcrypto and libssl libraries. There are m .so(shared object) files that contain cryptography functions. OpenSSL installation on Linux box cause creation of these .so files which contain cartographic functions.
Let us understand this by an example, as we know ssh server implemented through file /usr/sbin/sshd executable file. Further detailing , through ldd command, we can notice that libcrypto.so.x file present in /lib directory is used by /usr/sbin/sshd.
Now this is apparent that libcrypto.so.10 file is used by /usr/sbin/sshd to implement cryptography functions. Elaborating further reveal that, this libcrypto.so.10 file is created due to installation of openssl