File formats are a unified way which softwares would know how to open and evaluate the content.
Comma-separated Values (.csv)
chr,position,orientation
chr1,89009884,+
chrX,14400933,-
Tab-delimited Text (.txt)
date patientID proviral_load
2023-07-01 M100544 100
2023-10-01 F123455 40
Will not be covered here, but you may come across them - e.g. XML, JSON, TOML - often have dedicated packages for reading into R.
Will not be covered here, but you may come across them - e.g. VCF, SAM, FASTA - often have dedicated packages for reading into R - search https://www.bioconductor.org