I have listed some of the comparisons between SOQL and SOSL:
| SOQL | SOSL |
| Using SOQL, we search against the org’s database. | Using SOSL, we don’t know in which object or field the data resides. |
| The results after searching the data include matches for the exact search string. | We can find object or field in the most efficient and fastest way possible. |
| Using SOQL, we know in which objects or fields the data resides. | We can fetch data for a specific term which we know exists within a field because SOSL can tokenize multiple terms within a field and build a search index for this. |
| Using SOQL, we can search at a time only one object. | SOSL query can search many objects at a time. |
| Using SOQL, we can fetch all fields with any type of datatypes. | Using SOSL, we can search the only datatype of text, phone, and email type records. |
| SOQL is used in Triggers and classes. | In SOSL, classes are used but Triggers are not in use. |
| SOQL query performs DML operations on query results. | Using SOSL query, DML operations are not allowed. |
| We can fetch data from single or multiple objects which are related to one another. | SOSL searches are faster and can return more relevant results. |
| We can count the number of records that meet specified criteria. | Depending on the search object, SOSL searches also take advantage of the advanced features of the search index. |
| We can get sorted results as part of the query. | We can fetch multiple objects and fields that might or might not be related to one another comfortably. |
| We can fetch data from number, date, or checkbox fields. | We can fetch data for a particular division and find it in the most efficient way possible in an org using the divisions' feature. |